Curio events are disabled while being reworked. The party order thing is also way worse than just front line getting pushed back, I think its tied to puppies knockback but not certain, Ive had my entire party shuffled several times. My best guess is that a knockback affect is persistently pushing back their position in battle, so you can reset their spot out of battle in the out of combat battle formation, and they will use that formation to start in battle, but each turn it pushes them back in the out of combat battle formation, so after the fight suddenly the character is in the back again. So one a effect isn't clearing, and two a pushback is effecting the out of combat formation which it shouldn't. Its worth noting the push back is consistent in how it changes the party positions and the reason I suspect puppies is while I wasn't fully tracking it, they show up about as often as the effect and have a push back attack.
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The party order thing is also way worse than just front line getting pushed back
I've given up on simply bugfixing that piece of logic, and instead wrote a piece of code that verifies every combat whether something went wrong and warns me about it.
By now, I've found two bugs surrounding it. The primary one being that while it stored your initial starting order before combat (so it could reset it later), it would never clear that list. So you'd start every subsequent in the same position as your first combat, which becomes worse if that includes some girls that aren't even in the active party anymore since it persists between dungeons.
I expect some more bugs surrounding it will pop out of this check while I work on other stuff.