Ping times slowly build up to around 3000ms and then time out. After a few lost packets, pings are again 20ms for a while until the cycle repeats

We’re trying to use ZeroTier to facilitate connections from ERP software running on an Azure VM to a credit card terminal at the remote locations. The endpoints with ZeroTier installed are all running Windows.

Here’s a screenshot of what I’m seeing.

I have ZeroTier installed at several locations. The locations with this issue have Comcast modem/router combos. I’ve tried with UPNP enabled and disabled. I’ve also tried forwarding port 9993UDP through to the PC that needs ZeroTier on it. Nothing has made a difference so far.

I’m doing some testing with between my PC on Windstream behind a SonicWall to the Azure VM and that is working flawlessly. However, none of the Comcast locations are working reliably.