This is very upsetting to me.
My Mac would to wake after it went to sleep without a hard restart (and eventually not at all), and when it did there seemed to be a problem where the cursor froze, then 2 minutes later the Mac shut itself down and restarted. This ALSO happened in SAFE mode! Repeatedly (like 20 times).
I had sent my new 16" MBP back to Apple 2 weeks ago for this issue. They replaced the logic board and sent it back. Then, 4 days later this issue occurred again, and again and again....it would not even stay on long enough to reinstall the system.
I sent it back to them and was told they could not reproduce the issue. They just sent it back to me - INTERESTINGLY, with it running 10.15.3, and NOT 10.15.4, which is what I told them I had the problem with after updating. No mention of it in the repair writeup either. Now, as of yesterday, I am running 10.15.4, but have not really challenged it with large file movements or other intensive apps. I think I will not until I see an update.
I am pissed off, as I am a professor and need my MBP to teach online now and it seems this is something they know about and are not addressing in writing to any of us. Plus it has cost me two weeks and I just found this thread, so I know I am not alone. Life is stressful enough for all of us now, and Apple should do better. Much better for the cost of these machines - I would love it if an extended warranty were offered, as I no longer trust it.