After running 3.9.12 ~30 hours, it has started grabbing >95% CPU time after running ~60 seconds. This is AFTER shared files have been scanned, AFTER the connections have been established.

I have backed down to earlier versions, even rebooted, yet it now occurs with 3.9.12 every time I run it. It isn't at all obvious what it can be because it isn't caused by any user interaction, but if I had to GUESS, I'd wonder if it didn have something to do with the regular out-of-memory messages I have been getting.