ZM stops - daily

[Zotter]

Greetings! Looking for pointers on where to discover what's wrong here. I know something's not right, but don't know what clues are pertinent.

Long running ZM install on a dedicated box - several upgrades over the years and to date, it's been good. Installed from RPM, currently on Fedora 34 and at 1.36.5
6 cameras - all doing motion detect.
1G LAN. Storage shows about %48 usage (900G RAID). load shows about 4.x
98G of RAM, 16 cores (Xeon at 3.2Ghz). Database is 436.5 MiB

Recently, I'll log in to find current status as 'STOPPED' - will restart from either CLI (sytemctl - yes, is enabled) or web iface and appear to run just fine, until it stops again about a day or so later. Some days, it doesn't stop. Others it won't make it a day.

Looking at logs - many, many 'red' entries. But, I'm not seeing anything that screams "this is why it stopped".
Common and repeating entries for zmc_m(1-6) - "Error 67 occurred". Could that be it?

Any resources to help understand what Error 67 means? Or better yet, how to figure out why this thing is stopping?

TIA

[burger]

Please attach the full log output, preferably in debug mode.