My first problem with the nostrocket problem tracker is that I can't seem to log problems 😂 . So I'll do it here for now.

Problem: This will probably become an infintely nested tree of problems. So indentation is not gonna work past 20 or so levels (on desktop, let alone mobile).

Possible solution:

Combining Miller columns with an Email inbox-like layout could be something. You can still see the parents and easily scroll back or expand a certain level again and you have a clear overview of all the problems on the same level.

Also, on the opened level I'd avoid an extra click on a problem and already show the necessary info and buttons (log subproblem, status, tag, claimed by...)

Lastly, a sidebar menu seems better to me for this kind of app. Keeps nested notifications/categories in sight.