Thanks for your update.
We suspect that you use the "ng serve" command to run the application in development mode, and if so, the SCSS will be complied in runtime, which may affect the initial loading. We suggest you use the command "ng build --prod" to build the application in production mode, which will place the compiled files in the “dist” folder.
Initial loading is usually affected by the size of script and style files, and we ask you to check all of your non-Syncfusion dependency reference. We've also created a sample with Sidebar, Grid and Calendar in Angular where we can't reproduce the reported issue in development and production mode.
You must either host the application in a webserver or use any of the available local webservers such as the "live-server" NPM package / Web Server for Chrome to check the production build.
- Open the Command Prompt of your machine.
- Install the “live-server” NPM package using “npm i live-server -g”.
- Navigate to the sample location.
- Open the command Prompt form the ”dist” folder of the sample.
- Run the command “live-server” to run the sample using the production build.
Note: For Angular 8 applications, target in “tsconfig.json” should be “es5”.
Please get back to us if you need any further assistance on this.
Jesus Arockia Sankaran S