2 gear sensors at the same time

The Edge only allows you to connect to one ANT+ Shifting compliant device at a time. I don't think I have ever seen a mixed system before. 

Thanks for your reply. Not what I hoped for. But it is what it is

Is there a reason you did not put a SRAM front shifter on the bike? Cost?

I have a 3T Exploro racemax and the fixation of front derailleur broke twice. Very annoying.  So I decided, with my 3T dealer, to switch to Classified to ‘replace’ the front derailleur. 

Yes, SRAM Force is too cheap. ;-)

Just kidding. The Classified hub shifts better and the bike looks cleaner.

Pro: It shifts under load.
Con: It doesn't mix well with SRAM or Shimano and as I learned now: I have to guess which of my virtual chainrings is active.

I also have the classified power hub instead of a front derailleur, but in my case a Shimano Di2 for the rear.
I can pair both systems but only one is displayed on the bike-computer (Edge 1030 plus).
As Classified told me, the Wahoo bike-computer can handle this, Garmin seems to think nobody would use such a combination.
As Classified comes more and more also to the pro teams, they will loose more an more against Wahoo. Is that the intention?

Could you give a little more information.

The manufacturer, product, part number for the front and rear component.

Ideally supply the settings.fit from the Garmin\Settings folder as this will contain the pairing information.

Manufacturer of the powershift hub is Classified (https://www.classified-cycling.cc/). They have this one power shift hub (with several different rims.
The rear component is Shimano GRX RD-RX815, Di2. The bike also has Shimano Junction-A, EW-RS910 - EW WU111.

Settings.fit is attached.Settings.fit.zip
.fit extension is not allowed so I zipped it...