Since identifying this issue I have been restarting my hub more often and watching the mDNS spikes. This has improved my LAN performance, eliminated the audio issues on meetings, and eliminated my RDP issues.
New feature in 2.3.9.184
The mDNS restarts is what has been causing the huge spikes in traffic, even if you are not using HK or Hub Mesh (which both need mDNS).
Personally, I recommended that EVERYONE should turn this OFF (defaults to On).
If you are using the HomeKit integration and start seeing the dreaded "no response" afterwards, then you may need to turn it back on again. Turning this off should have no impact on HubMesh.
Settings > Network Setup
Here is my testing results:
Orange = 183 (same as 184) HK enabled, Bonjour Restarts Disabled
Blue = 182 (beta) HK Disabled
Pink = 180 (prior production version) HK Disabled
