Yes, yes and yes. I tried all the possible combinations, but ultimately nothing has helped with getting current out of the analogue outs of the UFX+ when using Thunderbolt. Also, there is no input signal when on Thunderbolt: when I stick my guitar direct into the UFX, there is no meter movement on neither TotalMix or the unit itself. Changing to USB cures this, but alas, glitches occur. I'm on the Kernel driver version of Thunderbolt (v1.23) and the latest firmware v165. The DriverKit driver made no change.
What I've done to get audio out of the UFX+ is to use my MADI AD/DA unit for this, as we know that digital signal was coming out anyway. I now have sound, and there have been no glitches since. If I switch back to USB, a glitch will occur sooner or later. This is still on Sonoma, by the way. So Thunderbolt and my UFX+ seems to be the answer somewhat, but it's very peculiar that there is no analogue in or out with Thunderbolt, and that it suddenly appears when switching to USB
EDIT: Might I also add, that the Thunderbolt connection has enabled my ability to use the UFX+ in Zoom again, as per to the USB connection which crashed Zoom whenever the Audio settings were opened.
FireFace UFX+ (Thunderbolt)
MacBook Pro M1 Pro (Sonoma)