One other point of advice: use a low impedance/solenoid tester when trouble shooting. The "phantom voltage" from capacitive coupling can confuse you even further.
I know this may have nothing to do with the OPs question in a way but... with many of us now pulling two neutrals because of the gfci breakers, does this mean we connect the two neutrals to the neutral slot on a 240v 4 wire outlet? Or do we leave one loose?
As far as i know you can't handle tie gfci breakers. You need a 240v/2 pole gfci breaker. I don't think two single pole gfci breakers would even work sharing neutral
You can't run the neutrals as you described on a branch circuit, that's would be considered a "parallel" neutral.