Might this happen because the comments have been meta comments to posts that have not been published?

@saunders scenario:

1. Using sub-domains for collections
2. Having meta-comments on not published post (which visibility do those posts have?)

Not sure if any of the points above have something to do with the timeouts. Let's check and try to reproduce.

What is the value of $cron_timeout_delay at your conf/_advanced.php file?
Do you get similar jobs correctly executed?

@mgsolipa

1. Yes; using sub-domains for collections
2. $cron_timeout_delay is 30 minutes (1800).

At first I thought it is caused because the comments (meta) refer to posts not being published yet (draft).
But this happens also with normal comments on published posts.

You guys need to focus on the difference between jobs that DON'T timeout and jobs that do.

@saunders please post a much longer log containing both successful jobs and timed out jobs.

Otherwise it's a guessing game. But while I'm at it: my guess is: everything that sends emails times out on your server.

@fplanque thanks for your repley. I deleted all timeout messages and the meta comments that may have caused this. I will trigger that timeout again and then I will send a longer job log.
Meanwhile, Greetings and Regards!