I'm having a similar problem, but I don't have restaurants/dine out. My adult vampires are constantly clearing their queue and ending conversations/actions/etc to get up and drink plasma packs from their inventory, even when their thirst bar is basically full. They do this both on their home lot, public parks, and the willow creek gym (tho I'm not sure if they'll do this on other lots, because parks+the gym are the only ones they ever visit consistently). I've only noticed the excessive drinking in one save file (I only have two saves I regularly play). I do have some mods installed, mccc, wonderful whims, etc, and two of my mods are vampire specific, a mod to slow thirst decay and one that adds a feature to make plasma packs from plasma fruit.
Gonna leave this comment here so I can come back to this post if I get a chance to playtest without the mods 🙂🤞
