Hello!

I have Fireface UFX III connected via stock USB 3 to USB-C cable. There is a problem in macOS Sonoma 14.5.

There is no sound output when calls in FaceTime, Google Meet on regular Software Playback AN 1/2. Any other system audio works fine and even "calling sound" in these appls works fine (as well as a "Test sound") and passing to AN1/2, but as a call started — there is no sound from the participants of the call.

They hear me fine (I have managed the RME's Loopback approach), but I can't hear them.

The only workaround I have found is to install Rogue Amoeba Loopback, create a new virtual interface and pass through any sounds via this app to Fireface UFX III's Software playbacks input AN 1/2. Then Fireface UFX III works fine and I can hear the participants. See the attachment.

Despite Rogue Amoeba Loopback works almost fine, it costs $100 and is not so convenient in use on the regular basis.

• I heard that there is a bug inside macOS: it fails to handle audio interfaces with so many inputs and outputs, especially in these calling apps like FaceTime.

• Also I heard that the problem is with USB 3. Because when I connected my second RME device which is USB 2.0 — Babyface Pro FS, everything worked just fine from the start.

• Also I heard that a probably workaround could be not to use DriverKit driver, but old-wayish KEXT driver instead. Is that true? Can anybody confirm that?

Dear RME team, could you confirm the bug and offer any workarounds or fix for that, please?