Hand aggregation from multiple devices does not seem to consider the screentop device

[wetoo-cando]

Hello,

I'm following this: https://docs.ultraleap.com/unity-api/Preview/aggregation.html. I have configured a scene based on the Aggregation Provider Examples from the "Ultraleap Tracking Preview" plugin (v6.7.0). I have two devices, one in desktop mode and the other one in screentop mode (see images below).

I'm hoping to robustify the hand tracking using a multi-view setup, as my application has very low tolerance for the estimation jitter from a single device.

I enabled "Debug Joint Origins", and specified debug color as white for the desktop device, and black for screentop one. However the resulting hands always show white joints and never any shades of grey or black. In other words, the aggregator seems not to consider the data from the screentop device at all.

Any ideas what could be wrong?

Device 1 configured for desktop mode operation

Device 2 configured for screentop mode operation

And the aggregation provider is configured thus