diff --git a/install.sh b/install.sh
index 1b2b114d..6d791bb0 100644
--- a/install.sh
+++ b/install.sh
@@ -297,7 +297,7 @@ setup_ssl_certificate() {
     if [ $? -ne 0 ]; then
         echo -e "${yellow}Failed to issue certificate for ${domain}${plain}"
         echo -e "${yellow}Please ensure port 80 is open and try again later with: x-ui${plain}"
-        rm -rf ~/.acme.sh/${domain} 2> /dev/null
+        rm -rf ~/.acme.sh/${domain} ~/.acme.sh/${domain}_ecc 2> /dev/null
         rm -rf "$certPath" 2> /dev/null
         return 1
     fi
@@ -431,8 +431,8 @@ setup_ip_certificate() {
         echo -e "${red}Failed to issue IP certificate${plain}"
         echo -e "${yellow}Please ensure port ${WebPort} is reachable (or forwarded from external port 80)${plain}"
         # Cleanup acme.sh data for both IPv4 and IPv6 if specified
-        rm -rf ~/.acme.sh/${ipv4} 2> /dev/null
-        [[ -n "$ipv6" ]] && rm -rf ~/.acme.sh/${ipv6} 2> /dev/null
+        rm -rf ~/.acme.sh/${ipv4} ~/.acme.sh/${ipv4}_ecc 2> /dev/null
+        [[ -n "$ipv6" ]] && rm -rf ~/.acme.sh/${ipv6} ~/.acme.sh/${ipv6}_ecc 2> /dev/null
         rm -rf ${certDir} 2> /dev/null
         return 1
     fi
@@ -451,8 +451,8 @@ setup_ip_certificate() {
     if [[ ! -f "${certDir}/fullchain.pem" || ! -f "${certDir}/privkey.pem" ]]; then
         echo -e "${red}Certificate files not found after installation${plain}"
         # Cleanup acme.sh data for both IPv4 and IPv6 if specified
-        rm -rf ~/.acme.sh/${ipv4} 2> /dev/null
-        [[ -n "$ipv6" ]] && rm -rf ~/.acme.sh/${ipv6} 2> /dev/null
+        rm -rf ~/.acme.sh/${ipv4} ~/.acme.sh/${ipv4}_ecc 2> /dev/null
+        [[ -n "$ipv6" ]] && rm -rf ~/.acme.sh/${ipv6} ~/.acme.sh/${ipv6}_ecc 2> /dev/null
         rm -rf ${certDir} 2> /dev/null
         return 1
     fi
@@ -524,14 +524,30 @@ ssl_cert_issue() {
     echo -e "${green}Your domain is: ${domain}, checking it...${plain}"
     SSL_ISSUED_DOMAIN="${domain}"
 
-    # detect existing certificate and reuse it if present
+    # detect existing certificate and reuse it only if its files are actually
+    # present and non-empty. acme.sh stores ECC certs under ${domain}_ecc and RSA
+    # certs under ${domain}; a failed issuance can leave a domain entry in --list
+    # with no usable cert files, which must not be reused (it produces a 0-byte
+    # fullchain.pem). Broken partial state is cleaned up so issuance can proceed.
     local cert_exists=0
     if ~/.acme.sh/acme.sh --list 2> /dev/null | awk '{print $1}' | grep -Fxq "${domain}"; then
-        cert_exists=1
-        local certInfo=$(~/.acme.sh/acme.sh --list 2> /dev/null | grep -F "${domain}")
-        echo -e "${yellow}Existing certificate found for ${domain}, will reuse it.${plain}"
-        [[ -n "${certInfo}" ]] && echo "$certInfo"
-    else
+        local acmeCertDir=""
+        if [[ -s ~/.acme.sh/${domain}_ecc/fullchain.cer && -s ~/.acme.sh/${domain}_ecc/${domain}.key ]]; then
+            acmeCertDir=~/.acme.sh/${domain}_ecc
+        elif [[ -s ~/.acme.sh/${domain}/fullchain.cer && -s ~/.acme.sh/${domain}/${domain}.key ]]; then
+            acmeCertDir=~/.acme.sh/${domain}
+        fi
+        if [[ -n "${acmeCertDir}" ]]; then
+            cert_exists=1
+            local certInfo=$(~/.acme.sh/acme.sh --list 2> /dev/null | grep -F "${domain}")
+            echo -e "${yellow}Existing certificate found for ${domain}, will reuse it.${plain}"
+            [[ -n "${certInfo}" ]] && echo "$certInfo"
+        else
+            echo -e "${yellow}Found incomplete acme.sh state for ${domain} (no valid certificate files); cleaning it up and re-issuing.${plain}"
+            rm -rf ~/.acme.sh/${domain} ~/.acme.sh/${domain}_ecc
+        fi
+    fi
+    if [[ ${cert_exists} -eq 0 ]]; then
         echo -e "${green}Your domain is ready for issuing certificates now...${plain}"
     fi
 
@@ -563,7 +579,7 @@ ssl_cert_issue() {
         ~/.acme.sh/acme.sh --issue -d ${domain} --listen-v6 --standalone --httpport ${WebPort} --force
         if [ $? -ne 0 ]; then
             echo -e "${red}Issuing certificate failed, please check logs.${plain}"
-            rm -rf ~/.acme.sh/${domain}
+            rm -rf ~/.acme.sh/${domain} ~/.acme.sh/${domain}_ecc
             systemctl start x-ui 2> /dev/null || rc-service x-ui start 2> /dev/null
             return 1
         else
@@ -617,7 +633,7 @@ ssl_cert_issue() {
     else
         echo -e "${red}Installing certificate failed, exiting.${plain}"
         if [[ ${cert_exists} -eq 0 ]]; then
-            rm -rf ~/.acme.sh/${domain}
+            rm -rf ~/.acme.sh/${domain} ~/.acme.sh/${domain}_ecc
         fi
         systemctl start x-ui 2> /dev/null || rc-service x-ui start 2> /dev/null
         return 1
diff --git a/x-ui.sh b/x-ui.sh
index 9b79d933..ee0f3763 100644
--- a/x-ui.sh
+++ b/x-ui.sh
@@ -1269,6 +1269,16 @@ ssl_cert_issue_main() {
                         echo "Panel paths set for domain: $domain"
                         echo "  - Certificate File: $webCertFile"
                         echo "  - Private Key File: $webKeyFile"
+                        # Register the acme.sh install-cert hook so auto-renewal copies the
+                        # renewed cert to these paths and reloads the panel. Without it acme.sh
+                        # renews but never updates /root/cert, silently serving a stale cert.
+                        if command -v ~/.acme.sh/acme.sh &> /dev/null && ~/.acme.sh/acme.sh --list 2> /dev/null | awk '{print $1}' | grep -Fxq "${domain}"; then
+                            ~/.acme.sh/acme.sh --installcert -d "${domain}" \
+                                --key-file "${webKeyFile}" \
+                                --fullchain-file "${webCertFile}" \
+                                --reloadcmd "x-ui restart" 2>&1 || true
+                            echo "Registered acme.sh auto-renewal hook for ${domain}."
+                        fi
                         restart
                     else
                         echo "Certificate or private key not found for domain: $domain."
@@ -1448,8 +1458,8 @@ ssl_cert_issue_for_ip() {
         LOGE "Failed to issue certificate for IP: ${server_ip}"
         LOGE "Make sure port ${WebPort} is open and the server is accessible from the internet"
         # Cleanup acme.sh data for both IPv4 and IPv6 if specified
-        rm -rf ~/.acme.sh/${server_ip} 2> /dev/null
-        [[ -n "$ipv6_addr" ]] && rm -rf ~/.acme.sh/${ipv6_addr} 2> /dev/null
+        rm -rf ~/.acme.sh/${server_ip} ~/.acme.sh/${server_ip}_ecc 2> /dev/null
+        [[ -n "$ipv6_addr" ]] && rm -rf ~/.acme.sh/${ipv6_addr} ~/.acme.sh/${ipv6_addr}_ecc 2> /dev/null
         rm -rf ${certPath} 2> /dev/null
         return 1
     else
@@ -1468,8 +1478,8 @@ ssl_cert_issue_for_ip() {
     if [[ ! -f "${certPath}/fullchain.pem" || ! -f "${certPath}/privkey.pem" ]]; then
         LOGE "Certificate files not found after installation"
         # Cleanup acme.sh data for both IPv4 and IPv6 if specified
-        rm -rf ~/.acme.sh/${server_ip} 2> /dev/null
-        [[ -n "$ipv6_addr" ]] && rm -rf ~/.acme.sh/${ipv6_addr} 2> /dev/null
+        rm -rf ~/.acme.sh/${server_ip} ~/.acme.sh/${server_ip}_ecc 2> /dev/null
+        [[ -n "$ipv6_addr" ]] && rm -rf ~/.acme.sh/${ipv6_addr} ~/.acme.sh/${ipv6_addr}_ecc 2> /dev/null
         rm -rf ${certPath} 2> /dev/null
         return 1
     fi
@@ -1576,14 +1586,30 @@ ssl_cert_issue() {
     LOGD "Your domain is: ${domain}, checking it..."
     SSL_ISSUED_DOMAIN="${domain}"
 
-    # detect existing certificate and reuse it if present
+    # detect existing certificate and reuse it only if its files are actually
+    # present and non-empty. acme.sh stores ECC certs under ${domain}_ecc and RSA
+    # certs under ${domain}; a failed issuance can leave a domain entry in --list
+    # with no usable cert files, which must not be reused (it produces a 0-byte
+    # fullchain.pem). Broken partial state is cleaned up so issuance can proceed.
     local cert_exists=0
     if ~/.acme.sh/acme.sh --list 2> /dev/null | awk '{print $1}' | grep -Fxq "${domain}"; then
-        cert_exists=1
-        local certInfo=$(~/.acme.sh/acme.sh --list 2> /dev/null | grep -F "${domain}")
-        LOGI "Existing certificate found for ${domain}, will reuse it."
-        [[ -n "${certInfo}" ]] && LOGI "${certInfo}"
-    else
+        local acmeCertDir=""
+        if [[ -s ~/.acme.sh/${domain}_ecc/fullchain.cer && -s ~/.acme.sh/${domain}_ecc/${domain}.key ]]; then
+            acmeCertDir=~/.acme.sh/${domain}_ecc
+        elif [[ -s ~/.acme.sh/${domain}/fullchain.cer && -s ~/.acme.sh/${domain}/${domain}.key ]]; then
+            acmeCertDir=~/.acme.sh/${domain}
+        fi
+        if [[ -n "${acmeCertDir}" ]]; then
+            cert_exists=1
+            local certInfo=$(~/.acme.sh/acme.sh --list 2> /dev/null | grep -F "${domain}")
+            LOGI "Existing certificate found for ${domain}, will reuse it."
+            [[ -n "${certInfo}" ]] && LOGI "${certInfo}"
+        else
+            LOGW "Found incomplete acme.sh state for ${domain} (no valid certificate files); cleaning it up and re-issuing."
+            rm -rf ~/.acme.sh/${domain} ~/.acme.sh/${domain}_ecc
+        fi
+    fi
+    if [[ ${cert_exists} -eq 0 ]]; then
         LOGI "Your domain is ready for issuing certificates now..."
     fi
 
@@ -1611,7 +1637,7 @@ ssl_cert_issue() {
         ~/.acme.sh/acme.sh --issue -d ${domain} --listen-v6 --standalone --httpport ${WebPort} --force
         if [ $? -ne 0 ]; then
             LOGE "Issuing certificate failed, please check logs."
-            rm -rf ~/.acme.sh/${domain}
+            rm -rf ~/.acme.sh/${domain} ~/.acme.sh/${domain}_ecc
             exit 1
         else
             LOGE "Issuing certificate succeeded, installing certificates..."
@@ -1664,7 +1690,7 @@ ssl_cert_issue() {
     else
         LOGE "Installing certificate failed, exiting."
         if [[ ${cert_exists} -eq 0 ]]; then
-            rm -rf ~/.acme.sh/${domain}
+            rm -rf ~/.acme.sh/${domain} ~/.acme.sh/${domain}_ecc
         fi
         exit 1
     fi