Why are Find My location alerts delayed or not working on iPhone?

Me and my girlfriend set up our find my apps to send each other notifications when either of us would leave and arrive to our homes, it was working perfectly for about a month or two then suddenly it wouldn’t send notifications when I would leave or get back to my house, and recently it started sending her notifications when I would leave but they’re hours late from the time I actually left. I still get notifications from when she leaves and arrives but mine aren’t working.