See the pink sticky thread above the posts with "iOS14" in the title.
-------------------- John --------------------
I do not work for VM. My services: HD TV on VIP (+ Sky Sports & Movies & BT sport), x3 V6 boxes (1 wired 2 WiFi,) SH2 in modem mode with Airport Extreme Router +2 Airport Express's. On VIVID200, Talk Anytime Phone, x2 Mobile SIM only iPhones.
iOS 14 displays a Weak Security message when the Hub is set to its default security setting. By default, Virginmedia Hubs use WPA-PSK/WPA2-PSK security so that older devices can still connect. It displays this just because WPA-PSK is an older Wi-Fi security standard.
Navigate to 192.168.0.1 then sign in and go to Advanced settings > Wireless > Security, next click the dropdown next to Security, and change it from WPA-PSK/WPA2-PSK to WPA2-PSK. If you separated your WiFi networks you'll need to perform these steps for both 2.4 and 5GHz.
** I work for VirginMedia but all opinions posted here are my own.