Jimster480
Major Contributor
I agree.The "REC SRC SEL" (record source select) button would be for selecting between an input source. Since it toggles between "2-TR" (e.g. a two track line level out device) and "IN 1/2" (what it labels the XLR input) this is the likely culprit. Behringer stuff is not great but usually not this bad. I think it's worth testing again.
I've had a few different Behringer products and while they aren't the greatest by a stretch, they are usually not totally broken. Their documentation can definitely be trash though.