What are connection like on devices connected to the Hub directly on ethernat cables? If you don't know, can you check to help diagnose whether it is just a wifi issue or it could be network connection/Hub related?
What Hub model is it?
Might be worth a reset - as per this...
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Do a Hub “pinhole reset” - first make sure the 2 passwords on the Hub sticker are still there and legible first ! With the Hub still "switched on" throughout, press the reset pin in firmly with paper clip/SIM tray tool or similar "thin thing" and hold it firmly for at least 60 (a timed sixty) seconds, release the pin, leave for 5’ to stabilise - dont manually switch it off at any time. Passwords and SSID’s will reset to those on the sticker so log in and change them back to what they were/should be.
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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.