Have you tried it with the failing male connector mated with a non-failing female connector. ie. using a good battery pack, (assume you
always put the female connector on battery and male on the load) with the same test, does it fail. If yes, then it is the male connector, if no, then test with a failing female conncetor and a non-failing male connector. Also, not throwing rocks but are they genuine Dean's conncetors and not knock offs?