WhatsApp and other sites slow to load and timing out

I have a real problem with WhatsApp Web in particular but also other sites as well when the site times out and I can't access it.

I have tried changing the DNS but this hasn't helped.

It's very frustrating

1) Reset TCP/IP Stack and Flush DNS.
Open Command Prompt as an admin, and run these commands, one by one:

ipconfig /flushdns
netsh winsock reset
netsh int ip reset

Restart the computer.
See if things are working properly.


2) Disable IPv6, temporarily:
Open: ncpa.cpl
Right-click your active network connection (Wi-Fi or Ethernet) and select Properties.
Uncheck Internet Protocol Version 6 (TCP/IPv6). Press OK and try refreshing a site that's not loading.