TACX (iPhone/iPad) for Work w/ XERT

Hi everyone and thanks in advanced for the support. I have a problem:

I have a TACX Neo 2T and the TACX app. 
The problem occurs when I need to perform a XERT workouts.
In this case, I should make sure NOT to associate the Trainer Neo T2 at the TACX App but only the power meter (Favero Assioma Duo).
And the trainer, paired w/ XERT Player on my Grmin Edge 1030-
This is to make XERT Player, on my Garmin Edge 1030, manage the trainer and the TACX App only displays the power measured by XERT.
In the settings, I only see the possibility of disconnecting the Trainer, but not the possibility of pairing the Favero Assioma Duo power meter.
I also notice that the ANT+ light, on the trainer, remains off, while the blue one of the BT is on.
Can you help me ? With Zwift or Rouvy, this option is possible: I can disconnect the trainer and only associate the power meter.
Simply put, the TACX app, the Favero Assioma Duo power meter does not see me. Do you have any tips or suggestions ? Thank so much !

Corrado, Italy-