That is expected behavior. The Flipper can’t use the BT radio while an app is using the radio.
Admittedly I have been very frustrated with the Bluetooth apps but here are some tips.
First make sure Bluetooth is turned on in the Flipper and the other devices menu.
When I pair the Flipper the app appears as Name Control and the second BT connection isFlipper name. I had to “Forget” both in the Bluetooth menu of my phone before I could get mine working properly. Once you get it working that might not be an issue the next time.
Open the Bluetooth app you want to use before trying to pair the Flipper. Then click “add new device” in the Bluetooth menu. If it still doesn’t work it may be already paired to that device or to another device.
If it won’t pair make sure it isn’t paired to another nearby device. The best way to do that is to “Forget device” before switching devices or turn Bluetooth off on other nearby devices you previously paired the Flipper to.
If it still won’t pair try “forget device” under the Bluetooth menu then try pairing again.
For me it works smoothly now