Cannot shut down my Mac Pro 2015 without forcing it by pressing the power button
It has been happening for past few weeks, maybe even months. I choose Shut down option from menu, all the apps close, everything on desktop disappears (menu bar, all icons), only background stays displayed with cursor being able to move on the screen. It stays like that for minutes and then goes to sleep after the set time but never shuts down unless I force it to.
It's an old mid 2015 boy, 15" i7 16GB ram, with Big Sur 11.6 macOS, otherwise working still quite well.
Can anyone please suggest a fix for it?
MacBook Pro 15″, macOS 11.6