I'm going down in rank/demoting after winning 7 games

This is my third time going through this where I’m winning more than I am losing and then going down in rank. I’m winning 7 before I even reach 7 losses and I’m demoting. There are some ladders where I haven’t even dropped one game yet I’m still having this issue. I’ve gone down all the way back to bronze 3 after this. Is this a bug or is it just poorly communicated game design?

Same thing happening to me winning constant comp games just to lose rank after the 7th win