One terminal of the volume pot is not properly grounded. It may look like it is, but t'ain't necessarily so. I suspect your soldering skills went out back for a smoke, when they should've remained on the job for a few more minutes.
Rule #1: All Lives Are Final. Make sure that the life you have just been issued is appropriate for your needs, before departing the womb.
Rule #2: In case you don't like the life you have, see Rule #1.