Two Zwift Sessions in same LAN,diff devices and logins


me and my wife wants to do our trainings at same time and done it for a while. I’m on my bike (KickrCore), she on our treadmill. Last week during Haute Route Group Workout I get in trouble as my wife starts her session on the iPad.
The whole time I got warnings to do more or less power etc. while my wife was made her training next to me. As he finished her zwift session I got no more warnings again. So we dine today some tests. I thought that it could be her Heart rate Monitor because I got in the past with it trouble on my bike riding outside. Because it disturb the communication between my cadence sensor and my wahoo roam.

But we found out, that we get the trouble by only starting zwift on a second device (we tried iPad Air, iPhone X an MacBook Pro) at the same time then our Zwift Notebook.

The Test situation: HP Notebook with an external ANT+ Sensor, disabled internal Bluetooth, Wahoo Kickr Core with newest Firmware (1.0.12), newest Zwift Release, Windows 10 (last updates installed). Connected to wired network

My wife uses Zwift Runpods, RunSocial TreadTracker and a Horizon Paragon 6 and a iPad air with good wifi.

what can we do to make it run in parallel?

Here are some pics of our config and results

Result with an mac instead of iPad:

with an iPad logged in:
IMG_8772 2