I had major problems with my keyboard, mouse and trackpad connecting
Worked on it all day and finally got it settled down
No issues now
I don't know if this helped, but got it off another Forum
Ran it in Terminal
sudo kextunload -b com.apple.iokit.BroadcomBluetoothHostControllerUSBTransport
sudo kextload -b com.apple.iokit.BroadcomBluetoothHostControllerUSBTransport
Was able to finally get everything reconnected after that
Your mileage may vary