Reading the recent replies it indeed might be USB Auto suspend. I've found a few links on how to disable that. One method is via Grub, but that's reported by some not to work (especially if you don't use Grub, duh). And it's risky, Grub is needed to start your computer's operating system(s). The other might work better (see link below).
First, try to determine if USB Autosuspend is on by the following (non-invasive) command:
Code: Select all
cat /sys/module/usbcore/parameters/autosuspend
A way to set it off is via TLP (which you've already installed, I read). Do what is said in this link.
BTW, what Behringer interface do you have? I've got the U-Phoria 404. The 202 is another popular model. I wouldn't know how to test USB Autosuspend but maybe I can help if you've got a similar device...
Good luck!