I've added a short text with artistic text tool. I've changed last character size (made it smaller) - it looked ok. But when I saved the file and reopened I got a mess - it looks like last character went on top of first one and they've been merged strangely together. I'm able to replicate it every time on my scene.
I'm on 2.9.6 .

Sounds like a real bug. It's getting clearer every day that we really need to rewrite the text objects....