Strange AI behavior?

Here’s a little backstory to start off with. I’m playing as Washington, and I had been at war with Northwest Territories-not a huge war, just tiny annoying skirmishes for territory every few days or so. I did end up in a larger battle with Oregon, and wanted my little skirmish buddy to calm down. I offered him a peace for peace deal through diplomacy, which went unanswered. Fast forward a few days and he abandons his game. Literally the moment the AI took over, it accepted the deal and withdrew its troops from 3 different skirmishes that it was clearly going to win (I had nobody nearby at the time)

Is that how the AI usually behaves? If so, how can that be used as an advantage? I understand the right of way thing with the AIs, but I’ve never had one cancel a war.