I’m not sure I have the exact same issue, but thought I’d join in with this thread.
My setup is windows laptop running zwift, wahoo kickr connected via Bluetooth. Laptop connected to TV via hdmi for big screen.
My issue is it feels like I am riding the resistance of the map profile in zwift of what appeared about 10 seconds previously. I have tried downgrading the Wahoo firmware to no avail. I have uninstalled and reinstalled zwift and the companion app to no avail. I have reinstalled a fresh version of Windows to no avail.
I have 2 work arounds which work - if I run zwift and the companion app together and use the companion app to connect the Bluetooth devices, this resolved the problem. This is then dependent on my mobile phone WiFi connection which is inconsistent.
The other is using my phone to run the full version of zwift, which would then use the mobile phone’s Bluetooth and WiFi again. This revolves the problem, but I have to watch on a phone screen rather than the TV on the wall.
I have ordered an ANT+ dongle for the laptop to exclude Bluetooth issues with the laptop. That should be arriving tomorrow hopefully.