A. Check if the app has any pending updates in the App Store. Sometimes, developers release patches to fix issues caused by OS updates. Go to the App Store, tap on your profile icon, and scroll down to see if OFP has an update available. If it does, update the app and check if the issue persists.
B. Try uninstalling and reinstalling the app. This can help reset any corrupted data that may have been caused by the iOS update. To do this, press and hold the OFP app icon until it jiggles, tap the 'X' to delete it, then go to the App Store to download it again.