I don't think this other issue is directly related to my problem but I have debugged it further.
The same error occured with Ubuntu Mate so I dug even deeper and I came across a topic on the official ZWO ASI forums where they were talking about different kernel versions (see
bbs.astronomy-imaging-camera.com/viewtopic.php?t=8253
)
The error message I got from _dmesg_ was
Ring expansion failed
usbfs: usb_submit_urb returned -12
My kernel version was 4.4.189-1230-rockchip-ayufan-gafadea9477b7 so I upgraded to 5.0.0-1092-ayufan-g58b7aac480ae and my issues were gone.
Now the USB-C port isn't working but the camera connected to the regular USB 3.0 port works without any problems and as a big plus the amp glow got better.