Heres how you replicate the bug… PLEASE Fix and reset rank!
1.Have your party leader search H2A Ranked
2. Have party leader back out while you stay on the searching screen
3. Have old party leader create a custom game and invite you
4. Join custom game
5. Party leader set kill score limit to 1
6. Kill party leader
7. Watch your rank go up
8. Repeat until x rank (takes longer to rank up the higher the skill gap between the players)