Please help! AI won't stop resigning

I have been working on a custom scenario game where waves of increasingly difficult enemies attack, but I'm running into a huge problem with the ai.

No matter what I try, the ai resigns halfway through the match. I've been looking for a solution online for the past few hours but haven't been able to find anything that works.

I tried this with original ai and standard ai (I'm playing on HD edition). I've even tried downloading the resonanceai on the steam workshop, but it resigns early just like the others.

Does anyone know a way to prevent the ai from resigning? I can't play my game until this is fixed.