UR22mkII problem with Mac OS 10.14.3

I’ve installed the latest driver ( Yamaha Steinberg USB Driver V1.10.4 ) for my UR22mkII audio interface on my new MacMini ( Mac OS 10.14.3 ). All installation steps were followed and I confirmed that the audio interface appears in audio devices after installation. The problem is that, when I have to restart the compute or when I turn it on next day, the audio interface simply disappears from the audio devices.
How can I solve this problem?


Make sure to have 10.14.4 and the latest driver 1.10.5 installed.
Then please also make sure to have a look at this article: https://helpcenter.steinberg.de/hc/en-us/articles/115001790330-macOS-Extension-blocked-message-during-hardware-installation

Thanks you for your answer, Ed. I’ve installed the Mac OS 10.14.4, the latest driver 1.10.5 but, still not working…
I have to unplug the usb cable from the audio interface and then plug it back in. So far, it’s the only way that I found to make my system work. Not very practical, I confess…