Yeah. Sorry for mixing up MR and PR (I work currently on a project with merge requests instead of pull requests).
I answered you previous post but got notification that Admin has to approve it and for some reason it never happened.
The behavior is that when the connection is lost watch always tries to reconnect for about 30-60 seconds (man plugging the connectors is shown).
The problem is that the phone ignores it unless screen is lit (phone unlocked or at least moved so that Motorola Always On Display is triggered).
I think this issue can be fixed on app side as there is exact behavior described on some stackoverflow pages - I cannot post links but you can search for "BLE scan stops on Samsung devices when screen is locked" and "BLE scan is not working when screen is off on Android 8.1.0". The fix seem to be quite easy and sounds even easier than changes in your PR although I'm not familiar enough with BLE or scan filters to confirm this on my own.
Unfortunately for Casio GB-5600B/6900B/X6900B are long forgotten watches and they simply don't want to fix the app for the watches no longer manufactured.