Sigma GPS Rox 11 struggling with 2 cadence inputs

[JeanMarc]

Hi there,
I bought a TREK bike which is Duo Trap sensor ready
So, I have a Duo Trap sensor installed on it: It is a Bontrager Speed / Cadence combo sensor which required one magnet on the rear wheel and one magnet on the non drive crank arm.
Also, I have a Quarq DZero powermeter installed on it: It is a Power sensor and also a Cadence sensor. In that case, the Cadence sensor doesn't call for any additional magnet.
To make it short, two cadence outputs are available and I want the one from the Quarq DZero unit to be used as it doesn't call for any additional magnet.
Here is the point:
As soon as the Duo Trap combo sensor is paired to the Sigma GPS Rox 11.0 unit I am using, then the Quarq Cadence input just turns ignored . Only the Duo Trap Cadence output is considered . As a result, the crank arm magnet has to be installed (otherwise my cadence would be 0)
So far I am clueless as to how address this concern.....
Any help would be welcome
Have a good day
Jean-Marc

[alcatraz]

I don't have any of your gear but with my sensors I had a similar issue.

On my garmin I can add the sensors as a set "speed/cadence" or individual as only "speed". I have both added.

When I use that wheelset on a bike with a power meter I have to disable the "speed/cadence" sensor which seems to take precedence. Then only speed gets picked up, and pwm cadence is displayed properly.

Don't ask me why it works the way it works. It does work however.

The ant+ id is different for a speed+cadence entry compared to a sole speed sensor. The sensor is the same one. All I'm doing is either using or not using the cadence sensor.

/a

[JeanMarc]

Thank you Alcatraz for your relevant feedback (speed/cadence" sensor which seems to take precedence makes a lot of sense to me)
In my case, should I disable (I mean unpair) the speed/cadence sensor, then the cadence from the powermeter is back but no speed gets picked up.
I have tried to have the Sigma GPS Rox 11 detecting a sole speed sensor but "empty" is returned... and I don't have any sole speed sensor ant+ id to propose....
Which make is your speed/cadence sensor ? Garmin? other?
Thank you
Jean-Marc