Find My and Location partially not working since iOS14

Since updating to iOS14, Find My, as well as location sharing through Messages, seems not to be working as intended. As shown below, when I open the Find My app, it asks me to sign in, but I can still see my other devices on the app. Despite saying I'm not signed, I can view the location of this iPhone and connected AirPods through Find My on a web browser, but the app itself seems to be having problems. Additionally, when trying to share my location through Messages, I get the error message, "Sign in to iCloud to Share Your Location. You can set up your iCloud account in Settings."

When I go to Settings > Apple ID > Find My (or Privacy > Location Services > Share My Location), I get the error, "Share My Location Unavailable. Unable to connect to server. Please try again later," whenever I try to toggle "Share My Location" on or off. Clicking "Use This iPhone as My Location" seems to do nothing.

So far I've tried:

• Restarting my phone

• Disabling and enabling Find My iPhone

• Toggling cellular and location services off and back on

• Signing out and back in to iCloud/Apple ID

• Disabling and enabling location services for Find My and Messages

• Erasing my phone and setting up from scratch

I also have upgraded my 11 Pro Max to a 12 Pro Max, and the issue that originated on the 11 persists on the 12. I have an iPad also running iOS 14, and everything on that device works as expected there.