Can't open memory map file /dev/shm/zm.mmap.1: No such file or directory

[onetoomany]

I'm getting a lot of the following errors in my logs:

• Unable to connect to monitor id 1 for streaming
  Can't open memory map file /dev/shm/zm.mmap.1: No such file or directory
  Monitor shm is not connected

Meanwhile, my cameras in montage view switch from showing image to being disconnected.
I've only got 4 cameras at 3MP, set for Modetect. I'm running this on a Ubuntu VM on a modern intel processor. I've allocated 20Gb of RAM in case it is a memory issue, which I assume should be plenty.

[bbunge]

Ubuntu version and database?

[onetoomany]

Ubuntu 22.04.1
MySQL 8.0.31-0

I've also noticed from the console I'm getting tons of Out of memory: killed process xxxxx messages.