Can a Mac enter sleep mode on schedule when a third party app tries to prevent sleep? There’s a third party software I have running on my Mac in the menu bar at all times, but for some reason it’s preventing my Mac mini from sleeping or locking the screen altogether. I contacted the company about this issue, but just in case I won’t be able to resolve it with them, is there a way I can prevent a Mac app from preventing it from sleeping, without quitting the app altogether?
No. Power manager assertions can be artificially created (e.g., via caffeinate) but they can’t be removed except by the app itself. You can, at least, view the current assertions via
pmset -g assertions

and see what kind of assertion your app has taken.