If you are finding that your connection drops after 20 minutes when using a Sky router, the following should fix the issue.
Using any web browser, log into the router by entering 192.168.0.1 in the address bar
Use “admin” and “sky” to log in
Select “LAN/IP setup” option
Scroll down the page and untick “Enable IPv6 on LAN side”
Click on “Apply” to save the setting