I recently updated to 2.3.1 and, since the update, my comment expiration setting does not seem to be working.
I have my channel preferences set for “Comment Expiration” at 90 days. This was the setting before the update and it still shows in my preferences after the update. However, comments are now open on all entries, including those older than 90 days.
Not sure it matters, but this is an MSM install.