I'm also adding to this because I am having the exact same problems with a client's 2017 27" 5K iMac with a 3TB Fusion drive running Monterey 12.4. Apple needs to address this issue as I have scoured the web and this is the only legitimate forum I can find discussing this unsolved issue. I am loath to spend the time and the commensurate expense to the customer remerging a Fusion drive that isn't broken ( https://support.apple.com/en-us/HT207584 ), reinstalling the Mac OS, and restoring from Time Machine just to have the problem reappear as is suggested by some of the above posts. Come on Apple, make an effort to FIX THIS PROBLEM.