Webpagetest Location


I was testing one of the UK Ecommerce site from London location. Before May 24th 2018, there were three options under London (EC2, Atlantic and other one (not able to remember)). From May 25th I can notice that last option under London was removed. Also I can observe major difference in response time between London 3rd option and Atlantic.net (atleast 15 secs difference).

Can you please let me know, whether London 3rd option is permanently removed and why there is a difference in response time between Atlantic and other options available under London.