USB-C audio dropout with RME Fireface UC audio interface

I am having constant issues with a USB audio interface crashing (losing all audio playback) following upgrading to a brand new 15" 2018 MBP.

It seems to be a USB-C issue, and can be triggered by lots of different other USB 2.0 peripherals (in a way that's not at all predictable ... sometimes plugging in the iPad, sometimes the track pad, sometimes an external HD) with a USB-C hub. It happens both with and without USB-C power pass-through (that is, it still happens if I have power only directly to the laptop), and it happens whether I have the audio interface plugged into the hub with the original USB 2.0 cable or if I use a dedicated USB-C to USB-b cable for the interface.

All audio stops once this crash happens—it is sudden and unpredictable. I can switch to internal audio, which works, but if I switch the output back to the RME interface it still does not play. The only option is to power down the interface and replug the cables, and sometimes I have to do a full restart of the laptop as well.

I'm on Mojave 10.14.1 (18B75). The RME Drivers are all up to date, as is the firmware. The USB-C hub is the 9-in-1 from Inkontech. (And, in case it's relevant, I'm using an external monitor connected through a USB-C to DisplayPort cable.)