Hi, charfurgie,
As you say, kerning (spacing) has been an issue with some titles. The problem has manifested particularly with the "Line" and "Lower Third" titles. Possibly there are other affected titles. Another user recently reported the issue again. It appears to be a bug, as no one on this forum has been able to find a reliable cure. It is definitely a frustrating issue where the spacing is critical to the effect that one is trying to create.
You might take a look at this thread, and particularly the thread link within it, to see if anything in there helps you:
https://discussions.apple.com/thread/250346844
Perhaps changing to a different title or changing the size of the default font after you have typed in your text might help.
You can also make your titles in the Preview app, where you can select the font and font size that you want. I have satisfactorily made some titles in the Keynote app that you can get for free at the app store.
I'm not entirely sure that Final Cut would not also have the kerning issue, as it might have some of the same title templates as iMovie. If you are considering buying it you might first want to post on the Final Cut forum to see if anyone there has experienced the issue. Same with Adobe.
-- Rich
