Side note: Are you blocking StayFree from accessing the network? Their ToS make it rather clear that they will collect & share all possible data they can get their hands on.
I'm not sure if I am or not. If it's not too much of a write-up, how might I be able to check? Is this something that can be changed in phone settings?
Thanks for letting me know. I wasn't aware of this otherwise.
By default all apps on Android have the permission to access the internet (and thus transfer any data they collected about you). The only way to prevent that is 1) using a custom ROM like GrapheneOS which allows you to block internet for chosen apps, or 2) using a firewall like NetGuard and blocking specific apps there.