Long Weekend Help

I’m working on finishing every achievement in the game, and I’ve been trying to get Long Weekend (finish in three days or less) and I’ve tried a couple times now, one with the Eternal Fate ending and one with the Failed Ritual ending, and it counts it in the review in the end credits, but I still haven’t gotten the actual achievement on steam for it. I’ve been trying to pair that one with ones like Insomnia (beat the game without sleeping) and the others in hat general theme (beat the game without showering, eating, making any friends, etc.) and cold shoulder (beat the game without saving with Sybil. As far as I know Explorer auto saves don’t count). I‘m not sure what I’m doing wrong. I know you have to have one with a final boss, but I have. Do I just have to actually *beat* whatever boss I end up fighting? Any help, tips, or recommendations for how I should do this is greatly appreciated!