SharePoint Online : yo @microsoft/sharepoint issue for BaseDialog API

Question

I developed sharepoint spfx extension for sharepoint online and created project through yeoman generator. From 2 years BaseDialog was showing properly and now sudden change from backend BaseDialog is showing abnormal behavior. It is working fine while opening the BaseDialog for the first time and disappearing for the second time. Due to this I am losing business with my client and trust in Microsoft cloud products. Both case screenshot

Below the environment details. 
+-- Node 16.14 
+-- @microsoft/generator-sharepoint@1.16.1
+-- generator-office@1.9.2
+-- gulp-cli@2.3.0
+-- yo@4.3.1   

     var dialog_1 = new CustomDialog();
          dialog_1.show().then(function () {
          });
       

 import { BaseDialog } from '@microsoft/sp-dialog';   
export default class CustomDialog  extends BaseDialog{
        public render(): void {  
            this.domElement.innerHTML=<h1> Hello World </h1>;
        }
    }