I come from the future to say that this happened to me too but not just with skjor. Vilkas does this annoying buggy thing where he doesn’t stop talking to me and following me so I lured him to some giants and got him killed after the companions quest. I’ve been playing the same play through for like a year now no mods and on ps4, it’s been months since he died and I got an inheritance right after he died. But today I was trying to lvl my smithing up and guess who interrupts me to say nothing, back from the dead, fricken vilkas. Though I took his Armor and set it up in my house he came back in his wolf gear again. Same with skjor he’s back with his outfit too. I don’t throw away my inheritance letters so I can remember who died if needed, a few days ago before he came back I was rereading his letter and laughing like a fool, today I checked again to confirm but all my inheritance letters bugged and now all say fridas name instead idk why. I threw them all on the ground after though. I can see how a bug like this benefits players who didn’t want them dead but I’m actually mad about vilkas and now need to kill him once again just so I can be freed from his bs