From the 9th June until to-day, the server in London has been unavailable for 6 days !
I can imagine that the London IP is very popular with Avast VPN customers, so perhaps a second server location in the UK could solve a lot of the problems which we have recently experienced, viz. availability of the server and (another thread) reliability of the connection.
PS. Just had a reply to my customer services ticket - apparently they "had problems with a server migration - should be solved now". So, change of server I guess...