I have a 40h - but Iām running Sierra these days so probably hard for me to replicate. I donāt recall ever having a problem where the lights stay locked on.
I have been trying to use the 40h with a raspberry pi, and occasionally it seems serialosc locks up.
Iāve fixed that by killing off serialosc and then restarting it. you can do that from the commandline in a terminal window - might be more convenient than rebooting your machine