Asking this here because on top of fixing the problem I really want to know WHY this is happening. For context, Amazon has been selling these boards for years under a constantly changing suite of companies with vaguely-techy sounding names. Here's a diagram of what we're dealing with. It doesn't seem to matter whether the switch is piggybacking off the motor's power or plugged directly into an outlet either via the onboard USB port or the two-terminal DC block.

Then either NO and COM or NC and COM (we tried both just to be thorough) are wired to the same terminals on the garage door motor that the physical button is wired to. It basically just acts as another method of briefly closing that circuit to tell the motor a button has been pressed. I've been using these for years and all of a sudden my father gets one and it's being a nightmare.

So after plugging it in we test the button and it works perfectly fine, but then once we test the RF remote the (usually ~13v) voltage between the two button terminals drops to 0 and none of the buttons/switches work anymore. This is incredibly frustrating as I know it's a stupid simple answer, I just can't see it right now. Any help is greatly appreciated.