Assioma Favero Duo & Edge 1050 - One Side only?

I have an issue wth my new Edge 1050 and my old Favero Assioma Duo Pedals:

I used the pedals for years in single-channel DUO mode connected via ANT on my Edge 1030/1040/Fenix/Epix without issues.
However, since switching to the 1050, I only get readings from the left pedal. The right pedal does not give any power numbers at all.

When using the same pedals on my Garmin Epix watch (also connected via ANT), I get proper readings from both sides. 
As I gave away my 1040, I can't test that, but it worked last week when I still had it. But as the Epix gets the corret power numbers still, I wonder if there is some weird 1050 specific software issue going on here as the pedals seem to be fine in general?

Anybody experienced something similar?

Cheers,
Christoph