Okay. Close that Opera profile, right-click on the Opera desktop shortcut for that profile, goto "properties", switch to the Shortcut tab, and edit the target field.
You want to remove --side-profile-muted from the target field command.
Now, for the pinned taskbar icon, you can do the same. Right-click it, right-click "Opera GX - profilename", click "properties", switch to the Shortcut tab, and edit the target field again.
Then, you'll be able to change the setting the way I mentioned earlier and it'll stick.