Bluetooth connection issues

I'm using an iMac 27" with macOS Sierra 10.12.6 and my trackpad quite often isn't paired, sometimes I have to restart, turn off bluetooth, turn on, sometimes it just comes back on.

I checked library/preferences and there is no 'com.apple.bluetooth.plist', but there is a com.apple.bluetoothAudio.plist.,

I had read deleting com.apple.bluetooth.plist and then shutdown, unplug, and re-plug should make it reappear, it didn't.

I also held down shift and option, clicked bluetooth, debug, reset bluetooth module with no luck.

Any suggestions??

Thanks