The audio hardware using the “Steinberg UR22mkII” audio driver was removed from the computer

Good morning.

I use the UR824 and UR22mkII. Recently when using the UR22mkII and Cubase 11 pro, the computer that I compose on crashes. When this happens, I get this message:

Audio Hardware Removed
The audio hardware using the “Steinberg UR22mkII” audio driver was removed from the computer.

The audio interface is connected to a 2017 iMac Pro. I updated the OSX from Catalina to Big Sur. Then installed the new UR22mkII USB Driver V3.1.1 and firmware for the Big Sur OSX. I thought the update fixed the problem but this morning it happened again. Has anyone had the same issue?