VM with HA messes up WiFi

It does not make sense that it is HA.
It could be your hypervisor or your router/AP.
If the hypervisor and router/AP have overlap in the subnet, then it can happen or if the AP is segmenting the WiFi networks.

  1. How many devices do you have on the 2.4Ghz band?
  2. Are these all HA related devices?
    If not: check if a non-HA related devices go offline as well.
  3. Check the logs from your AP, specifically for the 2.4Ghz band.

As @WallyR wrote: it doesn’t make sense that HA is cause for this.
HA is connected by ethernet to your LAN and communicates via your AP to the wireless devices.