Yes, the flows are getting slightly more complicated/better in the mean time, but I am not sure how much of a cause to the problem that is.
I have 3 RasPis running 24/7.
Way back when they would run happily for weeks/months between locking up and being needed to be power reset.
That wasn't too long ago. Maybe a few months.
Now, it seems I am lucky to get a week between the machine rebooting or locking up.
I have a watchdog running that resets the machine if it gets stuck. That works sometimes. Sometimes not. Then I have to power cycle it.
Background on the machines:
RasPi 2 (early one 2 USB ports and minimal GPIO pins) Stretch
RPZ (W) Stretch
RasPi 3b Rev 1.1 Buster.
Not accusing anyone of anything, but some things which I have noticed:
The amount of memory used is increasing - a lot.
I am suspicious there may be a memory leak (I think that is what they are called) which is filling up the usable memory and causing the machine to get locked up.
Weirdly enough the Early machine is the most stable.
There are other things which are being looked into as well. Alas I recently lost a machine twice in a short time. (Another story)
But the frequency that the machines are locking up....