Did you set all the location permissions properly? It is the most common source of not being able to find BLE devices in scans. Check Bluetooth permissions | Android Developers
Even settings Location permissions properly on latest Android versions is not possible to correctly do Ble scan for when the screen is off or the app is in the background (unless BackGround Access Location permission is not correctly set) for Samsung Devices
I push up this topic in order to wake up someone “on the samsung kingdom” to look at the problem because it’s not possibile to acquire wake locks to run background jobs.
Any other brand using Android do not blocks apps when consuming battery power and i tested it using same application, so what’s “the problem” ? and what can be the solution ?
It is not possible to initiate an unfiltered scan when the screen is off.
Please use a scan filter if it is necessary to initiate a scan when the device screen is turned off.