Inconsistent Sonobus Echo/Feedback

[WARF Radio]

Hi all,

Currently, we are using Sonobus for our Australian Rules Football broadcasts.

What we do, is that we have Sonobus on a standalone PC at our home studio, with the output muted. We only want to receive audio at this end.

At the grounds we broadcast, we have Sonobus installed on a laptop, receiving audio via Rodecaster Pro (from a USB-C to USB connection). 

We have switched on USB channel "mix-minus", so we can have the USB channel up/on, and in theory when we are doing back-to-back games from different grounds, both grounds are connected (with the home studio) to the Sonobus group, meaning we can talk (without delay) between the grounds live on-air.

However, this has proven to be inconsistent. 80% of the time it has worked, but a few weeks ago, I got feedback/echo at my end (ground 2), but no feedback was heard at ground 1.

Two nights ago, ground 1 threw to us, but couldn't hear us, we could hear ground 1, and the recording from the home studio end had us both going to air, but with echo/feedback.

I'm currently at a loss trying to figure out where the problem lays.