am at ch1 1:3 ch20 1:3 ch 40 1:6 it was ch 1 1:4 ch 20 1:1 ch40 1:3only if the extra 20ft is faulty or bad connectors as you discovered,
if the extra 20ft is perfect & you don't have cmc on the braid vswr should read a little lower with the longer coax due to more loss in the coax the further away from the feedpoint you place the meter/analyser,
tuning will change when you raise it higher above ground especially if you start near the ground.