BadDeviceToken from APNs for users after upgrading

Hi all,

For some reason we’re getting BadDeviceToken (error code 400) from APNs for approximately 1% of our users. We’re trying to debug this, but it’s baffling.

All affected users are now updated to the latest binary version (SDK 35), although the users we’ve seen with this issue were “late updaters” to SDK 35 and were running SDK 34 well into iOS 13. We know there were some bugs associated with that and BadDeviceToken, but our understanding is that after upgrading to SDK 35, they should have been resolved. We get the Expo token from Expo every time and save it to our server.

Any thoughts on where we can go in terms of debugging this? Ideally, we don’t want to ask our users to uninstall and reinstall, although that might fix it. (It’s kind of a bad look).

Thanks!
-Charlie