I have two hotspots and on both of them I find very difficult to connect via bluetooth to helium app.
I did reset phone bluetooth several times (turn BT off/on), reset hotspot few times and only sometimes I can pair with the device in helium app.
It usually takes 1-2 resets oh the hotspot and several resets of bluetooth on the phone to connect/pair.
I have a feeling that connection works better right after reset but it could be coincidence.
Please fix the BT or at least look at it