Apps not loading whilst connected to wifi

[M155YSW]

I have a lot of apps that don't load/work whilst connected to the WiFi. I have disabled sky shield and followed the steps in the help section. Emails don't appear until I turn WiFi off or leave the house. My heating app (halo) doesn't load, if I leave it long enough it comes up with the log in screen, but if I close it and switch WiFi off it is signed into the app automatically. Gumtree doesn't load. There is more but these are the apps I've tried this morning. Any help would be appreciated. All apps & software are up to date.

[mae-3]

@M155YSW 

When the wireless is working on other devices it is likely owing to that device being blocked by its settings on the device when a random MAC address is enabled (iPhone & modern Android phones), Sky don't like it enabled because they cannot establish whether it's a valid device on your home wireless network so they slow it down with firewall AI technology...

If every device is slow on wireless then one needs that sorting by Sky.