How to get the new interface for changing flights?
 

I've got a ticket with 8 segments that I'd like to see change options for online. When I click on Change flights in my reservation I'm taken to the below interface (accessible using this url: "https://www.united.com/ual/en/FI/flight-search/change-a-flight/changeflight/changeflight/rev?PNR="):

https://cimg6.ibsrv.net/gimg/www.fly...425310eaad.png

However, sometimes I've been taken to another more modern looking interface with the new deeper United-colour. I haven't been able to figure out what decides which interface I'm shown.

My questions is if there is a way for me to access this newer interface by choice? For example, does it have a specific url or is accessible from certain countries only?

The reason why I'm looking for the new interface is that with the old interface my flights are showing AAA-XXX-BBB-ZZZ-CCC as one segment, meaning I can only change all of them at once. With the new interface I've been able to change AAA-XXX-BBB and BBB-ZZZ-CCC separately.

If anyone is getting the new interface, could they please share the url with me?