I've been experiencing bad latency spikes and packet loss for the past three months. To give you an idea of how the state of my connection looks every day, here's a BQM of today:

As you can see, latency is spiky and I'm seeing packet loss at just about every hour of the day.
I am running my Superhub 3 in modem mode, and it is connected to a PC running PfSense for routing.
I've spoken to VM's customer support phone line three times:
- First call I was told there was no problem, the problem is with my kit, the Superhub is only designed to be used with four devices, running in modem mode is not a supported configuration, and as I was working from home I would only get support if I upgraded to a business plan.
- I called again a couple of days later. I was put on hold while the technician on the phone was looking into it and then was hung up on.
- I immediately called back and got through to a UK call centre. The technician was super helpful and agreed that something was strange as there appears to be no problems from their end. The call ended with him scheduling an engineer visit.
The engineer visited on the 25th of May and was great and tried his best to diagnose. He confirmed that all coaxial wiring inside and out was fine, power levels looked good, and there were no issues in the area. He also called a VM call centre and confirmed that my area is not seeing high utilisation. He requested a utilisation monitor on my connection for a week and texted me a week later saying that there is slight utilisation in the area but nothing that should affect service.
I've done a lot of troubleshooting and trying to pin down the cause of this, but the only thing that seems to have any correlation with other people's problems is a firmware update in early March and the fact I am in modem mode.
List of my troubleshooting:
- Tried various different devices as the router while the Superhub was in modem mode:
- Dell R710, R220, R210, Optiplex 3010, and an HP EliteDesk G1 900 (all with PfSense running on bare metal as well as in a VM running on ESXi)
- On the ones with PCIe slots, tested with on-board Ethernet ports as well as known good Intel Pro/1000 PT NICs
- Tried all with and without VLANs
- Tried rebooting the Superhub - makes no difference
- Replaced ethernet cables between Superhub and the router PC/server
- Checked that power supply is good and not getting too hot
- Checked that the Superhub isn't overheating - hard to tell in modem mode but it's not hot to the touch - just warm
- Superhub is out of direct sunlight at all times of the day
- Held the reset button on the Superhub in for 30 seconds, resetting it to router mode, then put it back into modem mode - no difference
The latency and packet loss gets worse when doing anything streamy - be that watching YouTube/Twitch, voice/video on Discord, Zoom, Google Meet, and Whatsapp calls. I've also noticed that doing something such as loading a webpage with lots of assets (such as Amazon or eBay) will trigger the issue more often than not. Speedtests seem to be fine though but things that need high numbers of connections or high packets per second seem particularly triggering. Curiously, Torrenting multiple Linux ISOs at the same time doesn't seem to do trigger the issue.
From the troubleshooting on my side and from VM's side I'm thinking that it's an issue somewhere between the coaxial port and ethernet port of the Superhub. Certainly after throwing so much of my own kit at trying to pin it down, all those computers, servers, ethernet ports, and software can't all be bad, right...?
I can provide BQMs from around the time I started having these issues but not before (because unfortunately my IP address had changed and I had forgotten to update the BQMs, but that's now set up on my DNS name so should be fine from now on). I have also started logging my own data from my side and have been pinging a VM in Google cloud, the next hop on the network, and my external IP address - when my connection goes down, pings to all three go down.
I am more than happy to provide any BQMs or my own ping data as well as do anything that will get me a stable internet connection. Also happy to speak with and troubleshoot with any VM tech. After three months of this, I just want a decent internet connection (which - up until March - VM was the only ISP capable of delivering to the property).