On the updated version of Tanki how do you leave the group, Ive taken them off my friends list and reloaded the browser. What do I do?

Hi, if you want to leave your friend group, click on your nickname in the top left corner of the interface (it is right above your experience bar), and then select "Leave group" from the context menu that appears.

Read everything you wanted to know about the Matchmaking System here. Have a sweet time battling with your friends! :)