Bluetooth issues between iPad Air and iPhone X

iPad Air iOS 13.5 and iPhone X iOS 13.5 won’t pair via Bluetooth. Both devices see each other and connect to other devices but not the iPad and iPhone. Tried loads of times implementing the suggested possible fixes for Bluetooth connectivity issue without success.

The options I have tried are:

1 Turning off Bluetooth on both devices, waited a few minutes before turning it back on.

2 Turned off both devices, then back on.

3 Carried out a hard reset, using the volume keys then the on/off button

4 Reset the network setting on both devices.

However non of these have corrected the problem and I keep getting “make sure devices are on, close to each other and discoverable” which they are. The last resort is to restore to default, “which I don’t want to do, for obvious reason” and thought maybe someone in this forum could offer up an alternative.