I use my MacBook Pro with Big Sur 11.6 on it as a backup for my Windows laptop and have no problems connecting but it is an older model. No drivers need to be installed. I usually power up the table before plugging in the USB connector. Any more info you can give about your set up?
Oh and I did accept the initial security allowances. Can’t remember what they were but that might be it.
Also it did say in the Langmuir Firecontrol docs when I first set up my laptop that Big Sur was not supported but I figured what the heck and tried it anyway. Has worked fine for me.
You might want to try installing the new Beta Release of Firecontrol and see if that connects