iPad Air: Choppy audio using an audio interface through USB-C to A (no issues when using lightning to usb)

I recently came into possession of a Tascam iU2 audio interface which provides an option to connect to my very old iPad 2 via 30pin connector, as well as (switchable) to anything else using the mini-usb port. It is a neat, compact device that does really well what I was looking for.

Then I tried pairing it up with my iPad Air 2021 using a usb-c hub (to four usb-a ports), but that did not work out well. The device looks to be recognized, but gives highly choppy snippets of sound. Even when putting another powered USB-A hub in between or using a different, indepentently powered breakout usb dongle/hub it shows the same behavior.

When pairing this thing up through an aftermarket lightning-to-usb-a dongle (be that powered or unpowered) with my girls' iPad 6 or my iPhone Xs, the interface works like a charm.

All devices were on the same iOS (somewhere between 15.1 and 15.3) version. I am assuming it has something to do with the USB-C protocol having a newer kind of power-management feature, but would be really curious if someone knows what is actually behind this.

The iU2 interface appears to be class compliant, as it is instantly recognized by Windows when plugging it in.

Not looking for answers of the sort 'get yourself a newer device'; where's the fun in that(?)