There’s a red “1” notification on the Settings button at the bottom right, but I have no idea what it is.
Clicking on the button just opens Settings, no markings saying what the notification is related to.
Poking around a couple of settings didn’t reveal anything.
On Android, v2.24.0
FIXED - It was a notification that an upgrade was available.
The bubble bug should be fixed in the newest version.
So the version this notification is for? Ironic.