Panic - Watchdog Timeout: no checkins from watchdogd in 185 seconds

This has happened on my Mac Pro ever since I received it in May and nothing seems to fix it. It will go a week (sometimes 2) and then it starts shutting down or rebooting every time I'm not using it for 2 or 3 days and then goes back to normal. Sometimes it will boot to the login screen and only sit there for a moment before restarting or rebooting. Sometimes after shutting down the system is dead as a doornail for 10 minutes before it will restart. Just so you know, I spent about two months working with Apple enterprise (June and July while running Catalina, now I'm on Big Sur) trying to get this resolved and sent them many many diagnostics. We decided it was probably a hardware issue . I took my Mac Pro to an Apple repair shop and left it there for the month of August. They said they couldn't reproduce it. Funny, as soon as I got it back it rebooted before I managed to even log in. Now we've talked Apple into replacing the graphics MPX module (W5700X) since the log files have a GPURestart error a dozen times before every shutdown. My point is that I'm thinking this watchdog shutdown isn't caused by just one thing. I think there are various possible things that cause it. Clearly most people having this issue have different hardware than I do and very few have the W5700X MPX module, so that is not the common thread. I do run my LG 5k monitor off from USB-C. However I swapped it out for my wife's LG 4k HDMI monitor and it still had the shutdown/reboot issue. I've done clean installs of Catalina and Big Sur and no other software with no luck. I'm out of ideas.

On my Mac Pro, it was being caused by the McAfee kext mandated by my employer. Started in safe mode, rock solid for three weeks. Started with McAfee, crash within a few hours. Has been up continuously since I was allowed to get rid of McAFee going on three weeks now with pretty close to 100% CPU utilization during that time. Just FYI.

This is a frustrating issue. I have a late 2013 27" iMac with one external monitor and 3 external drives, and this happens almost daily when I attempt a shutdown. I regularly run CleanMyMac and Disc Utility to make sure everything is clean and in proper order. Zero response from Apple when submitting this problem. I've run all the updates and am current and this still continues. Frustrating it is not being worked on.

Good feedback

obvious comment is get the 10.15.4 "combo" update.

https://support.apple.com/downloads/macos

.

CleanMyMac is a known cause of crashes. Get rid, if it lets you.

As it is a junk malware that clings like mud on a blanket it may be difficult.