I am using Ubuntu 22.04 and for quite some time (1+ year) I noticed that Base was getting horribly slow when operating a form connected to a MySQL 8 database. 

I decided to install the libreoffice ppa and update the version to 7.6.4.1 to see if that could fix the problem, but it didn't. I tried on 2 different computers (one with nvidia card and another with a hybrid intel+nvidia) and in all graphics combination the error is there. The most modern computer is a dell xps 15 with Intel i9 and Nvidia dedicated card, so it is quite a powerhouse for what is needed to run Libreoffice.

In the past, Base responsive, but now it is almost unusable. Even when selecting and deselecting a check box in a table control connected to a boolean field in a database table, the UI gets extremely slow, and the update takes 1.5+ seconds. During this period, X usage has huge and constant CPU usage spikes. Even trying to access Base's menu takes forever.

Researching for this type of problem, I noticed many users are having problems similar to this one, but not on Base.

With a lot of research, it seems the culprit is the package libreoffice-gtk3. If I uninstall the package, install libreoffice-kf5 and set 'export SAL_USE_VCLPLUGIN=kf5' in my .profile, then Base is really snappy and there are no problems at all (even Calc seems a bit faster), so it is not a database issue or connection to the database issue either.

Another thing that I noticed is that in the past it was very common to have Base crashing while editing a Form, but so far this hasn't happened with KF5.