Kuttoe has fixed this with a mod- seems that Stayover Calls' shared cooldown gets reset every time you load the game or even travel between lots. So they were basically permanently on cooldown forever, after the first one.
Now that it's been properly diagnosed, EA- let's fix this one! This is a big one and it affects more than stay-overs!
EA_Cade this bug is now pretty much fully player-diagnosed, so hopefully it can be escalated? This bug also explains other reports like the Bluffs and Ancient Ruins calls from Get Together not showing up, and the Mentorship Visit calls from Businesses and Hobbies- which I don't think anyone even knew were a thing. I'm betting testing on that one was done by forcing them to happen since it's not feasible to wait around for weeks and hope a random phone call shows up, so nobody on the team realized they werent working.
Details here:
https://kuttoe.itch.io/mini-mods-bug-fixes