Ubuntu Mate 20.04 vm - Entire Machine lockup (Random)

A couple of days ago I upgraded from PD 14 to 16. I did skip version 15. Too after upgrading I installed fresh Ubuntu Mate 20.04 with Compiz. I use it pretty much all day developing. I also have an 18.04 version and I have the same issue. So I do not believe it is related to VM.
Under heavy use entire machine locks up, fans start spinning up and the machine shut itself down at random times. If I do not have Parallels running machine is stable all day. I am ruing in rBP late 2013 (10.15.6 (19G2021)) and parallels 16 (ParallelsDesktop-16.0.0-48916.dmg).
I called support a couple of times and they are as useless as a donkey. They struggle with their own product trying to find "Take snapshot". On two occasions I was told someone from higher support will contact me within 24 hours and ... well, no one did. So I called today again and I explain again my issue (Original Ticket number 2786294). After spending 30 min on the phone I lost confidence in support. I asked to do logmein123 with him. After he joined I could quickly see that he is not prepared at all. I decided to drop that call after 30 min since it was pointless waiting for support finding his way around his own product.

So random lockup is my primary problem since I can not work. The other issue I also reported and added my comment in another post was trying to copy a file from within VM using "cp" command from Mac shared folder

$ cp /media/psf/VShare/dev-setup.tar .
cp: skipping file '/media/psf/VShare/dev-setup.tar', as it was replaced while being copied

I also noticed that VM at times is just stopped responding for 30 sec? and sometimes come back and at times machine does shut itself down.
Again when Parallels is not running I do not have any issues. Under PD 14 I never had any stability issues. I moved to 16 since I needed to install 20.04 VM and 14 had issues installing guests.

Here is what was done so far.
Technical data was uploaded to the ticket
I did boot to recovery and did check Data partition - no errors
Uninstalled and reinstalled PD 16
Reinstalled guest tools
Running all latest updates on all involved software.

Support (if you exists) please let me know what I should try and what info you need to get this resolved.

 

Here is htop running this VM. On host Safari and iMessage is open beside Parallels single VM running
Also some some reason I keel looking left mouse click at times in VM. Right works fine. Left at times does come back and starts working (maybe couple of min?). When left mouse is not working (I can not select text, click anything, etc but I can move cursor and right click does work. This is using building trackpad on my rMBP) everything seems to be working. Also when left click stops working inside VM, if I switch to Host it still works in host. Switching back to Guest it does not until wait some random time or reboot VM

 

Forgot to mentioned I have two cores allocated, and 6G RAM to this VM

 

Did try to downgrade to Parallels 14 but now my Guest is black screen on boot.
Can someone from support please give some direction? Please?

 

Hi, could you upgrade to the Parallels Desktop 16 once again, reproduce the issue and collect the technical report right after that?
Please do not forget to post report's ID here.