It is one of the oldest issues on GitHub. I assume you're using either AOSP Keyboard or OpenBoard, beacsue so far it seems that it only happens on those keyboards. I don't know about AOSP Keyboard, but with Openboard, in the Text Corrections section, if you disable "Show correction suggestions" it should work properly now. Link to issue: https://github.com/dessalines/jerboa/issues/194 There is a comment there from the user MV-GH who has posted a screenshot (it's near the bottom) of the option you need to toggle off and it will work properly. If you need correction suggestions, I'd recoomend either switching the keyboard or switching the client.

Worse: When jumping back and forth sometimes the text appears at another postion than the cursor and overwrites words it for some reason considers the one you are typing.

Yes, and it is very annoying. ~~However it does not seem to be happening now with Jerboa 0.0.42.~~

Edit: This is still happening for me too, as of Jerboa 0.0.42, with the AOSP keyboard. It does not happen in any other apps.

Yes. I have found you have to tap the end of the comment to erase any spaces there, then continue typing the comment. Otherwise it will type in the middle of a sentence somewhere.

As @theshatterstone54@feddit.uk suggested: Turning off auto correction ('Autokorrektur') solves the problem with my AOSP keyboard temporarily.

Let's hope there will be a better fix in the future, because as a non native english speaker I rely heavily on auto correction. Changing keyboard would be annoying, my fingers just got used to this one. And changing to another client than Jerboa would be sad as well, it's the only client on f-droid.

I've never not had this issue while writing a comment since I first downloaded it, back to v0.0.35 around 2 months ago. Hopefully it'll be addressed soon.

It's quite frustrating, but I ended up being used to work around it (mainly tapping multiple times to the end of the comment). Feels like whacking an old TV to make it work.

I have a similar issue with the line break and the numbers. Double tapping it will copy the last word word If I enter a number it wil also copy it4it.