diff --git a/server/model/monitor.js b/server/model/monitor.js
index 186962b08..b6e950322 100644
--- a/server/model/monitor.js
+++ b/server/model/monitor.js
@@ -548,7 +548,7 @@ class Monitor extends BeanModel {
                     log.debug("monitor:", `gRPC response: ${JSON.stringify(response)}`);
                     let responseData = response.data;
                     if (responseData.length > 50) {
-                        responseData = response.substring(0, 47) + "...";
+                        responseData = responseData.toString().substring(0, 47) + "...";
                     }
                     if (response.code !== 1) {
                         bean.status = DOWN;
diff --git a/server/server.js b/server/server.js
index 594c29b31..5473cecd4 100644
--- a/server/server.js
+++ b/server/server.js
@@ -714,6 +714,7 @@ let needSetup = false;
                 bean.authDomain = monitor.authDomain;
                 bean.grpcUrl = monitor.grpcUrl;
                 bean.grpcProtobuf = monitor.grpcProtobuf;
+                bean.grpcServiceName = monitor.grpcServiceName;
                 bean.grpcMethod = monitor.grpcMethod;
                 bean.grpcBody = monitor.grpcBody;
                 bean.grpcMetadata = monitor.grpcMetadata;
diff --git a/server/util-server.js b/server/util-server.js
index 0bf69133b..ffc3b3d95 100644
--- a/server/util-server.js
+++ b/server/util-server.js
@@ -787,7 +787,7 @@ module.exports.grpcQuery = async (options) => {
                     data: ""
                 });
             } else {
-                log.debug("monitor:", `gRPC response: ${response}`);
+                log.debug("monitor:", `gRPC response: ${JSON.stringify(response)}`);
                 return resolve({
                     code: 1,
                     errorMessage: "",