@sdetweil Hi, just wanted to update that the new image that is in MM page reference for Docker installation works well now and I can configure the custom css. Thanks.
Sorry took sometime to revert as was busy.

@sdetweil

Hi sir, this is the permission and files in the css folder. I hope I got what you need to know as I am still a junior in this.

I have the exact same issue too. Custom.css does not seem to work. Checked all permissions in the folder and file itself and they have the same permission settings. Looks like there is some limitation when using Synology Container Manager (Docker).