Service DEF, Regen Required... Just Kidding??

Doesn't matter how correctly you repair Weather-Pack connectors. Eventually the water and salt gets in anyway and that creates corrosion and bad connections. It's not like I'm unplugging stuff every day. About once a year, I might have a problem.

This latest time was the exact scenario the OP mentioned. Unplugging the connectors and plugging them back in, freshens up the metal-to-metal contact on the pins and sockets, a little silicone to help guard against new corrosion and it's good to go for a while. I consider it regular maintenance on a system that has miles of wiring.

If you have a method of lifetime guarantee wire connections, I'd be interested to hear it.