[Mark McLeod]

The connections sound correct.

It's very strange though that you'd happen to get both defective Digital sidecars.

With the lack of Batt and 5v status leds I'd suspect the 12v power feed from the distribution panel.
When you tried both side cars did you use the same power cable?

An immediate suspect is that the wago clamps at one end or the other are grabing insulation rather than wire.
Try pulling the 20a breaker (leaving the power distribution wago connections alone) and testing continuity of that cable with a meter.

After testing try removing the wire from both wago connector ends and reattaching them.