In my TiddlyWiki, when I select the content type (type) field and type a letter, it unselects that field and selects the text field instead.
I have to click back onto the type field to correct it.
It has been like this for the longest time, and I’m keen to resolve it. I don’t know the first thing on how to debug this though. Any ideas?
Which TW version do you use? At tiddlywiki.com there is no such problem, so it has to come from one of your modifications.
You can open the $:/ControlPanel → Info → Wiki Information tab. and click the button there.
You can post this info here as a whole if you want. Or you can only copy parts.
You can try to disable all your plugins if you open your wiki in safe-mode eg: https://tiddlywiki.com/#:safe
see: https://tiddlywiki.com/#SafeMode
At startup, it shows a list of disabled plugins.
You can test your editor and see if the problem is still there. If not → it’s one of you plugins
If the problem is still there, then it’s a modification that you made to your edit templates.
Hope that helps
-Mario
Thanks, I was able to work it out. It’s a core bug related to the $:/core/AutoFocus setting, where I prefer strongly prefer to first focus on text.*
* I personally prefer to come up with a title after I’ve done my writing. Just an artefact of the chaotic way I tend to think. I do the same with my emails too - writing the body first and then the subject.
I went to file a bug but it turns out it is already known - and you have commented on it too. 
Ahh. Ok. I should be fixed in the next TW version.
see GH PR : [Bugfix] - keep focus on Element with tc-keep-focus class by BurningTreeC · Pull Request #9233 · TiddlyWiki/TiddlyWiki5 · GitHub and
preview: https://deploy-preview-9233--tiddlywiki-previews.netlify.app/