Yes - protocol is below. The extender should still work with VM but if it isn't receiving a good enough signal from the "poundland" Hub. Try moving it to another plug socket closer to the Hub.
But TBH they are never great solutions. The best way to ensure full wifi coverage in your property is to connect Wireless Access Points directly to the Hub - or your own better router by ethernet cables.
However some would say a good Mesh will be the best/simplest/most flexible for most average users who dont want to run ethernet cables. A Tri-band Mesh system is better for the "backhaul" and for users on high speed packages and umpteen simultaneous connections. Wifi6 is future proofing too.
Another option is to extend the ethernet connections (and wifi) via powerline adaptors - they work well for lots of people - including for my "gaming son" in his bedroom and they can be "cheap and cheerful". These are far better than the "extenders" like yours.
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Type in
http://192.168.0.1 into your web browser’s url box and login with settings password on the Hub's base sticker (or your own if you changed it). Then in Advanced>wireless>smart wifi - tick the disable “channel optimisation” box or “Smart Wifi” box and save settings. Then, go to advanced>wireless>security, rename the 2.4 & 5 GHz network ssid's. Just change 'em to whatever you like and something that will differentiate them (e.g - xxxxx_2 & xxxxx_5) -- use the same password for simplicity, Then, apply settings and restart the Hub. Your 2 wifi networks will now be clearly separated - and you can then select the network you want to connect to individually from the "available networks" list on each device.
Note all your wifi devices will need re-connecting to the new SSID's and passwords.
5 GHz is always better/faster and subject to less interference (and is better for iDevices ) than the 2.4 one - although the 2.4 one has the better "range" and some older/cheaper/dumber devices can only use this one.
You should also use a wifi analyser App to check which 2.4 channels are being heavily used around you and move yours to one of numbers 1,6,11 that is least so, but it wont help if there is other interference.
See if these changes help - you will lose any “seamless roaming” benefits but it may not matter and you can always change the settings back by doing a " pinhole factory reset " if you prefer the way it was - or it doesn’t help.
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John
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I do not work for VM. My services: HD TV on VIP (+ Sky Sports & Movies & BT sport), x3 V6 boxes (1 wired, 2 on WiFi) Hub5 in modem mode with Apple Airport Extreme Router +2 Airport Express's & TP-Link Archer C64 WAP. On Volt 350Mbps, Talk Anytime Phone, x2 Mobile SIM only iPhones.