hey there,
i wish to share this situation, took us 4 hours troubleshooting:

setup: rme ufx 2 in a shared room.
- win 10 pc with studio 1 being in the room all time
- mac mojave laptop with cubase 10 pro brought and connected with rme ufx 2 to use the studio

- last week:
- incoming audio from input ch 3&4 was NOT transmitted to any daw on mac laptop anymore.
- tried possible routing issues, driver re-install, cubase connections, restarts, anything
- weird: just connect the usb cable to the windows machine and it worked fine
- resulting in: software? back to cubase, faulty project file maybe? new projects, no success
- friend suggested trying using his workspace file from win pc
- copied, loaded, TM fx on mac crashing (first time ever)
- checking TM fx versions
- mac: 1.66 win: 1.72
- separately downloaded 1.72 for mac
- installed
- audio from input ch 3&4 appearing in mac daw as usual
- relieve

So I still think about it: because a newer version of TM fx installed from an onto another computer makes audio disappear somewhat "internally" in the ufx 2 on another machine with an older version of TM fx? It really is that: on TM fx 1.66 on the mac, audio signal was appearing on TM fx, was playing back on speakers. But did not make its way into any DAW on mac. Internal input channels in DAW were showing up nothing, routing correct, just nothing coming in.
It all went to normal since TM fx mac was updated to 1.72.

have a nice weekend,
maik