Retrofit Problems

[Alneyan]

Demorve said:
A couple of them were [built by the enemy] but most of the ships were built by me.

You cannot repair technology you don't have, so enemy ships may be impossible to repair, depending on their tech; that would solve at least part of the problem, if it is the case.

Maybe having those impossible to repair ships "contaminate" the whole sector, and prevent any repair from taking place? It sounds unlikely, but who knows? And it is the least unlikely idea I can think of (except the usual "the user is bugged", but I have never been fond of that one).