Intel iMac Does Not See Discoverable Bluetooth Devices

I have an Intel iMac running Ventura 13.4.1(c) and it has suddenly lost connection to my bluetooth devices (e.g. Apple wireless keyboard, hearing aids). It no longer even detects nearby bluetooth devices. I tried clearing my previously connected bluetooth devices from the "My Devices" list in the bluetooth Settings page to see if that would help - but it has not.

This just happened all of a sudden.

Any help would be appreciated.

Thanks