Well that's wierd honestly because most of my waiting times are 50 seconds to 1:30 and the game has the cheeky to put me mid.
I select support/jungle or support/top and one case i did pick support/fill.
It could be that if someone dodges a lobby the timer still goes on and that can result in me getting thrown into other roles i didn't request for.
I think the last thing i said is true but i cannot 100% confirm it since I've given up on ranked because of this feature it may sound pathetic i know but its not just me that has this problem its having to listen to others who have the same problem so i rather not do any damage to my team and just stay out of ranked until something happens.
Still a bit grumpy over some recent changes which doesn't really help.
I hope you and everyone does good this season but im gonna sit this one out.