It looks like the same error I’ve been getting for over a month now after upgrading to 4.4.1. The only difference is that I don’t actually get the
Allowed memory size of 2147483648 bytes exhausted (tried to allocate 20480 bytes)
error in my PHP logs. I also don’t get the error when I run the command manually from the CLI. It only shows up when the task is run via cron.
Just today I downgraded to Matomo 4.3.1 to try to diagnose the issue further. I’ll post later with the results if they’re encouraging. (So far so good; it’s 5 minutes past the cron job’s scheduled execution time, and I haven’t gotten an error email yet!)
EDIT: downgrading to Matomo 4.3.1 did indeed stop the flood of email error messages!