started season got to rank 20 logged in next day and was at rank 25, got back to rank 16 or rank 18 (cant remember, i think it was 16 but probably 18) then knocked down to rank 20 chest said 18(?) log back in next day chest says 20… it keeps bouncing around and doesnt lock chest to my highest rank i got to…and knocks me back ranks when i havent lost games… i checked between wild and standard but theres no difference… has anyone else had this bug?
The type of Chest will only change every 5 ranks. At the end of the season you’ll always receive the Chest of the highest rank you reached for that season, even if you get knocked down.
Remember; Ranks and Hero Levels are different; don’t confuse the two. Ranks are your progress during a season, Levels are your progress towards unlocking Basic and Golden Basic cards and cap at Level 60 per Hero.
i edited it for you. i still want to know why when i logged out at rank 20, then logged back in next day i was at rank 25? then got to rank 16 or 18 and the chest said 16 or 18, but then next day i logged back in it said rank 20 was the highest i got…does it not lock in the highest rank you got too if you log out before it hits the 5th rank lvl? so i would have to get to rank 15 before i log out to lock in the chest otherwise it will just rerank to rank 20 the next time i log in? it hasnt done that to me in the past… when i get to rank 18 the chest stays that way till the end of season even though i drop ranks.
I had this too this season. Ended last season at 20, started this at 25, and a few days later boom, back at 20. Then a few days later I had dropped back to 24. This keeps on happening. Weird. Have climbed to 19 a few times so hope I get that chest though, and the bug is not that big 
Sounds like you’re switching between Wild and Standard formats. Each format tracks it’s own rank. For example, you can be Legend rank in Standard format and rank 25 in Wild format.