#skyrim bug

It's one of many bugs that affects the Proving Honor quest, in this case it prevents the quest from being completed properly. Essentially, Vilkas refuses to stand outside Jorrvaskr and wait for me, and the rest of the companions dont gather for the initiation ritual. The quest marker points to Skjor and talking to him is a dead end.

It's happening on the Switch version, so no console commands. I've looked all over the internet to find any way to fix it. Nothing helps. I've slept in Breezehome for 24 hours, waited outside Jorrvaskr for 12 hours, walked from Dustman's Cairn to Whiterun, reset my bounty, hell I've even reloaded to a save before joining the companions and completed the quests that apparently conflict with it before redoing the whole damn thing. Nothing. Works.

I have a lot of questions about this glitch. The most pressing is obviously how i can fix it, or alternately whether it can even be fixed. Ive tried everything i can find online barring giving up on the character. It's my boyfriend's save, and he is very against the idea.

Other questions i have include: What is actually causing this? I know there are mods out there that fix it, which must mean someone out there knows what causes it.

When does the glitch happen? It seems to be happening well before the questline even begins, at least in this case. Specifics would help me gauge how far back to reload if possible, or so my boyfriend knows what not to do with future characters.

I know this is a known bug, and it doesnt seem to have any documented fix for once it occurs. I have some experience with Skyrim's bugs, but this one is a serious doozy. It feels like all the methods ive tried are just troubleshooting methods rather than ways to fix the bug when it happens for real.