Having WPUA.1 = 1 caused leakage to VSS; it wasn't completely 0; varying in the 1.1mV range. My ADC reading never reached 0.
makes little sense , the wpu is approx 47k its impact on a 5k pot should not be noticeable , this may be indicative of a different problem




I took out the Port = 0 settings, set WPU properly instead of leaving ANSEL/TRIS override it, and now my ADC reading varies from 0 to 1.
ansel does not override wpu , what you claim makes zero sense

Has light jitter with this pot.
your power supply must be very noisy or the pots are complete crap [possibly microphonic] to get such poor results