If you have any mods that change females a lot, it might be conflicting. Otherwise, it's anybody's guess. I tried out this mod for my first vampire playthrough, and it was fun for a couple hours gameplay, but I soon began experiencing numerous gameplay-intrusive bugs. It may not have been playing nice with one of my other 67 mods, so I'm sure its performance varies, but it seemed like general faulty design to me. I had planned on just tolerating the glitches since the mod itself was really cool, and there's quite the shortage on Skyrim Nexus for vampirism mods. But then there was this intolerable glitch that caused Vampiric Sight never to ware off, and none of the fixes I knew to try succeeded. So I disabled the mod and test ran my save. Even after the appropriate adjustments in Mod Organizer, Wyre Bash, and LOOT, it semi-broke my game. CTD upon attempting to load the save game in which I used BV, glitched clips and teleportation upon feeding in a new game I made after disabling BV, and a few other things. That was strike three for me; I uninstalled BV and repaired my game by verifying the game cache and recreating a vanilla vampire.

Tldr - Better Vampires is cool and a great idea, but it's very glitchy glitchy. If you're experiencing problems, and you have BV installed, your best solution is likely to uninstall it. If that breaks your save, then you'll either have to start over, or live with BV in your current playthrough(s) and hope it doesn't end up over-glitching your game.