Di2 question: Shifters ST-R785 won't play nice with FD-R8050

[weisan]

When I connect the FD-R8050 directly using SM-PCE1, eTube recognizes the unit immediately and it passes the test check with no problem.

The problem arises when I connect the rest of the setup with shifters ST-R785 shifters, etube will only recognize the shifters but fail to recognize the FD-R8050.

One tell tale sign: if I connect the FD-8050 just using the charger SM-BCR2 and a junction box, it won't recognize either.

Off the computer, on the bike, the left shifter is not talking to the FD either, it won't shift.

Interestingly enough, when I connect that same FD to another bike that is running GRX di2, it shifts no problem. It begs the question: is ST-R785 incompatible with FD-R8050? Both are 11 speed.

What else could be the problem? Thanks for your help.


FD1 by Wei San Hui, on Flickr

FD4 by Wei San Hui, on Flickr

FD5 by Wei San Hui, on Flickr[/QUOTE]