Mitel softphone one-way speech (InAttend, MiCollab) due to antivirus

Picking up audio issues like one-way speech or no speech? And probably you have the following working:

1. Can record a voice snippet fine using an audio recording program. So the device is working and drivers are good.
2. Tried analog line inputs and USB headsets.
3. Wireshark might only show RTP packets in one direction: but there is no firewall or routing involved (same subnet).

So here is the possible culprit: antivirus. Especially Kaspersky (or maybe that is the one I come across the most)

I am just posting this save someone a week or two of troubleshooting in the future...