Yes, I'm beginning to think that as well. I have contacted them and here's what they asked (with my answers.)
If connecting to a USB type C port, ensure the USB cable is either one we have approved or is one that is ‘USB IF’ certified. (done)
Does any specific action (or actions) seem to cause the disconnection? For example, connecting headphones, switching on 48V phantom power, etc. (NO)
Do you have access to another computer to test this on? If so, what is the outcome here? (HAVEN'T TRIED)
Do you have access to a powered USB hub? If so, does connecting the 4i4 to this have any impact on the problem. (YES AND NO)