No amperage reading from 1 panel of 5 total

Hello,

I have 5 Renogy 100w panels connected to my charge controller in parallel.

I've used my tester (set on DC Amps) to test the amperage readings of each panel. Considering my install and the angle I've placed the panels, my tester is reading about 4 amps output per panel (for four of the 5 panels) However, the first panel (1 of 5) in my array is not showing any appreciable amperage output on my tester. When I test the leads of this panel (with my voltage tester) I'm getting about 20 volts.

The connectors I'm using seem to be fine with no apparent damage. If the first panel (with no amperage output) is indicating 20v output... are the diodes suspect? Or, should I be looking at the cable connectors to find the issue?

Thanks!