Bluetooth doesn't find any bluetooth devices anymore after updating the 10.13 Security-Update 2019-03
I have updated now to macOS 10.14.5 and now I can turn off the bluetooth what was not possible under macOS 10.13
I already did all the procedure like SMC reset, PRAM reset, resetting the bluetooth device with shift-alt-klick. nothing really helped.
MacBook Pro 15", macOS 10.14