Disconnecting due to upgrade, or something else?

On Thursday evening I called VM to negotiate my contract price down, as it ends next month. This weekend and the agent also offered me an update from 125mbps to 250mbps which I accepted. To do this she 'sent an update' to my hub which disconnected my services for what felt like a long time, about 20 mins. Even the agent was a bit confused why it took so long. Eventually my router showed a yellowy orange steady light, which again was confusing but I've since leaned could just be a broken white LED.

Anyway, yesterday (Friday) all was fine but this morning (Saturday) the service disconnects every few minutes. It will work fine, at full speed, for about 10-15 mins then everything will disconnect. The lights on the router don't seem to change. I've tried restarting the hub, disconnecting devices etc and get hopeful it's worked, then the same thing happens. I checked the VM status page and it says there are no issues in my area.

I've never really had any issues with VM for a few years so it seems a strange coincidence this is happening so soon after the 'upgrade' but I can't understand how something like sending a hub update could cause this drop in connectivity.

Or is it just a coincidence?

Any wisdom much appreciated.