I’d encourage everyone to update to Pleroma 2.5.0 (https://pleroma.social/announcements/2022/12/23/pleroma-release-2.5.0/).
There are lots of performance improvements in this release. If you still experience breaking timelines after the upgrade, please do the following:
Check if you have changed the postgresql settings to the recommended ones. The defaults are TOO LOW! See this link for the settings.
Run a vacuum analyze on the database to update index information.
Consider upgrading postgresql to the current version (15). There have been many improvements in postgres, too! The upgrade is probably easier than you think. You can download the db to your computer, perform the update there and then upload the new database to your server, if you want.
If all of this fails and you still experience bad performance, please contact me and I’ll try to figure out the reason with you and fix it if it’s a problem in Pleroma.