No Reliable Map Rotation for Team Slayer

Hey guys,
So I’m not sure if this constant issue is happening as frequent to everybody else, as it is to me.
but most nights when playing for example Ranked slayer, I find myself playing same maps over and over with no hope of getting one outside of Mercy. It makes the game completely un enjoyable. I don’t understand why this issue still haven’t gotten fixed And for arena , the first three games that I get Will be the 3 I will get the rest of the night.