Question about Teambuilder...

I was going to put this in Report a bug but I'm not entirely sure it is one. Maybe Riot just intended for this to happen for some silly reason...

Is teambuilder supposed to be repeatedly placing me in a lobby I've just left? I know that 'matchmaking knows best', but when I leave a shaco/nasus botlane because I don't wanna be a part of those shenanigans, it's because I DON'T.

At first I thought it was a random thing, but this also happened to me the other day when I kept getting put in the same lobby with an ekko jg (also something I don't do).

I click find another group because I want ANOTHER group.

Has anyone else had this happen to them, and if so why is it happening??