Things like this are regularly reported and often due to faulty firmware on the hub. There's no prospect of any imminent fix, especially because the majority of customers don't change wifi settings from the default, so VM don't really worry too much about those who do.
I can offer a guaranteed fix, although you may not like it, of buying your own mesh or router, and running the hub in modem mode. That puts all wifi settings under your control, stops any meddling by VM in the setup, and will normally provide better wifi coverage. If you want to do this, then allow £60 for a basic but competent router, or £100 for a basic but competent mesh. If it's a smaller property or an easy wifi environment then a two pack mesh for seventy quid would be a solid choice. I'm using a TP-Link Deco M4, and that's worked a treat. If you go down this route I've found it best to leave the mesh to its own devices in terms of channel and frequency choices - if you are intent on dabbling in the channels and detailed setup, then an Asus router may be the way to go.
