I legit can't remember now which specific one it was a year later. I think it had something to do with items and physics, I just remember being incredibly frustrated at seeing something I'd also seen in a semi-recent unmodded Morrowind playthrough (my first ever so the bugs were FRESH in my mind as I'd never seen them in a playthrough before)
All dialogue options have previews that are nothing like what you actually say (Looking at you Cyberpunk) so you try to apologise for someones loss but the actual dialogue is your character being an utter piece of shit without warning. Getting the true ending and several important pieces of gear require you to never be mean to multiple NPCs.
Reminds me at the start of witcher 3 my brother was playing and some thugs come annoy you, one option was something like 'I disagree' which sounds reasonable, so he picked it. That option has Gerald insulting them and jumping straight into a fight, shit escalated fucking quickly lol
Or the tone of the actual responses doesn't match the text for the selection of the responses.
"Do you accept the mission?"
Yes
No, thanks
Maybe...
Option 3 actually declares war on quest giver.
Oh and one that just happened to me last night:
Your normal actions still work during dialog so if you press buttons to try to exit out of a dialog, you might accidentally attack the NPC you're talking to. If you let them kill you, they are still hostile when you return. Need to start a new save to recover. At least they drop the unique key from their shop when you kill them (Dark Souls 1, hopefully it's no big deal that I had to kill the blacksmith. At least I don't have to listen to the pounding metal when I spawn above him anymore).
In BG3 Lae'zel asked to be with me and she said "if not now, then later" and I said something like "no thanks" and it permanently locked me out of romancing her.