If you actually go through the thread: https://forum.treeofsavior.com/t/report-3-bugs-npc-market-ui/115142
It’s been clearly mentioned that the rest of their party members DO see it, so being in one or not is extremely irrelevant, at best it could’ve been a party leader only issue, but this wasn’t the case, which is why, point already proven that it’s false.
Again, from a coding point of view, this is an extremely big hassle to ADD this kind of ‘feature’ to prevent you from obtaining the quest, while not meeting a list of requirements is a simple true/false check list before seeing it.