Were multiple workers working before in this setup or were you always hitting this issue?

It’s hard to tell. I’ve used multiple workers with code samples I found online. They also ran out of memory for no good reason, but only if I used a large number of workers. Using 1-2 workers seemed to work fine. Using 8 workers (corresponding to the number of CPU cores in my machine) complains about lack of memory even though the system has plenty left.
When I try using multiple workers in my own (custom) project, I can’t even use one worker.
I suspect there is a bug with workers, but my specific project triggers that bug earlier than other projects.