Not gaining ELO for Winning?

So I need help because i dont know whats wrong with my accounts ELO progression. I’m currently 94% from Diamond 1 (Onyx 3 right now) and no matter how many games i play and win i DO NOT gain ANY ELO. Is this due to enemy players leaving right before the match ends? like i need to know because i’m grinding for D1 in the KOTH playlist but i am just stuck… also a day or two ago i went on a 5 game winning streak and NO ELO GAIN Please Help!