Ok. Let me clarify.
So when using the windows 11 theme, any shortcut icons or folders that I have altered via the change icon option that are pinned to the start menu no longer have the custom changed icon look and have instead reverted to the original default icons.
When using windows 10 theme this is also true, but if I enable the experimental tile option then the icons also will change to the new icons so it seems the experimental option is also preventing custom changed icons.
Interesting thought...
If switching on and off experimental tile option is what is causing this behavior, what would happen if the experimental tile option was also added to windows 11 theme? That could be fun...
Edit. The computer just needs to be restarted for icons to take affect. You can disregard, although interesting thought can stay.