I was thinking of that. I am wondering if the USB mapping is getting mixed up, will try this tomorrow. My machine wouldn't update from Catalina to Big Sur, it would just freeze, I'm guessing from kernel panic but can't seem to get the point where the installer panics. I had Big Sur 11.1 working, but lost it when I was trying to fix a Linux problem. I will try your suggestion tomorrow and let you know what the result is.