Ex’s find my friend notifications popping up on my iPad

So my ex broke his phone and I let him use my iPad. I signed out of my Apple ID and he signed into his. When I logged back into my account, I noticed his photos were merged in with mine, which wasn’t a big deal at the time. Now a year later, I’m getting find my friend notifications saying his family members started sharing location with me. My iPad and iPhone are synced cause of iCloud, but I only get these notifications on my iPad. I’ve checked everywhere, I’ve logged in and logged out, idk where it’s coming from. I also can’t update my apps all of a sudden because it wants me to put in his Apple password. I saw someone say on a thread in here that my ex must’ve downloaded an app and I need to find it delete it and whatever. I talked to Apple support and she said she same thing. But she said she has no idea how I’m getting these find my friend notifications. Has anyone else experienced this? Any solutions? Thanks