Sorry to say, Eddie, that this is a common grounding problem that’s symptomatic of a number of causes (eg. a single cold solder joint or short among a dozen that all appear fine).
I myself am helpless without my coke bottle-glasses and magnifier; so I feel bad asserting that a visual inspection is step 1. The most compromised, low-tech attempt I can suggest is to use a square of electrical tape to make sure the grounding points on the bottom of the pots are pressed into making sufficient contact, but even that won’t necessarily overcome a cold solder joint.