If you actually want to fuss with it you could always try some of the stuff from the Holy Wiki and see if it makes a difference. Sometimes it's just "gremlins" though.

I ironically had a similar issue with moving to Wayland from X. I did everything I saw documented to make it work and it just either flat out didn't, or performance was ass. Then I think when I had read about Gnome's future plans to drop X I figured I needed to give it another go. In the end I'm not sure what made the difference (update/config/etc.), but I'm using Wayland now and performance seems the same/better and all is good. My install is also probably close to a decade old (or more - I have moved it between at least 3 disks) at this point so I also have cruft out the ass lol.

Edit - Got curious and decided to look and this install is dated 2013-02-24, so longer than I thought.