Android app randomly assigns 5 digit number as sound, thus, no alert sound is played

For several months now, my Ring App on Android will randomly assign the notification sound for door rings to a random 5 digit number. There is no sound named that number, so nothing rings!I've found this on both my Ring App and the Rapid Ring app.If I set it correctly, it will inevitably change back to the random 5 digit number. I have not identified when it does this per se.It is a very odd bug and has caused missed rings because there is no audio notification as a result.