Bluetooth has spinning wheel where the button should be

I have an older iPad Pro (12.9-inch) wifi 128Gb that was working great until iOS 15. I use an app the uses bluetooth to connect to another iPad pro same model which does not have the same issue. The only difference in the 2 iPads is in memory (256gb vs 128 gb) and radio (it has wifi + cellular).

The app starting cutting out when I was not at home. When the 2 devices are on the same wifi (at home) the app re-routes over wifi. The bluetooth icon in the control center is blue and indicating on...

...but in Settings where the bluetooth on/off button should be all i see is a spinning wheel.

The other iPad Pro with cellular has none of the same bluetooth issues?

I tried the network re-set, shut-down and restart and toggled airport on/off. Not sure what else I can try.