diff --git a/BACKEND/app/services/line_connection.ts b/BACKEND/app/services/line_connection.ts
index 9e1e38d..a03d3f9 100644
--- a/BACKEND/app/services/line_connection.ts
+++ b/BACKEND/app/services/line_connection.ts
@@ -272,6 +272,7 @@ export default class LineConnection {
   async writeCommand(cmd: string | Buffer<ArrayBuffer>, userName = '') {
     if (this.client.destroyed) {
       console.log(`⚠️ Cannot send, line ${this.config.lineNumber} is closed`)
+      this.disconnect()
       // this.disconnect()
       // await sleep(2000)
       // await this.connect()