I am seeing this happen as well.

I am losing rank's win OR lose in regular unranked play... This normally happens if I am playing ranked first then move to unranked play.

SAme happened to me . https://clips.twitch.tv/LachrymoseDiligentHerdDancingBanana

Same thing happened to me. Played 10 - 15 ranked games, everything working like it should. Switched to unranked and about the 2nd or 3rd game in won, but upon winning on the Victory screen it showed my rank going down. Switched back to a ranked game to see what would happen, won and rank went up as expected. Switched back to unranked, won and Victory screen showed ranking go up this time. Breaking even on unranked errors affect on ranking at least...

Had the same issue.

This did not happen the second time I played. Maybe it was a weird one time thing. Going to try again.

I also had this problem. I went into a regular game to try out a deck but it ranked me down when i lost even though it wasn't ranked

Winning or losing in nonranked play makes me lose rank. Ranked play appears to be unaffected.

I've been playing Historic Ranked all morning and switched to regular "Play" mode and played a game. When I finished the game it ranked me up in Standard. I have confirmed that I did NOT play a Ranked match, and indeed, since I got the update for ZR, I do not have a "Standard Ranked" deck selected.

I played a standard unranked match, that I WON, the opponent roped me, then after the match I LOST rank.

Same just happened to me!

I'm playing in limited format, but no matter if I win or lose I get a notification for my constructed rank. I've had my constructed rank (Platinum 3) go down for a loss in the non-ranked play mode, and I think I had my constructed rank go down for a win, when I was playing a Limited, Sealed match. I tried to figure out how to do a screenshot, but they all just look like I got done playing a regular constructed match, so I didn't think they'd be useful here.

I've never played Sealed format before, but if I'm supposed to be ranking up my Limited rank for that, I am not. I'm 3 wins in here, but my rank hasn't moved up at all.

When playing 'Play' matches my constructed rank is changing after some matches.

i played a standard game and lost, for that loose i lost in standard rank too.

Just lost a match in normal unranked play while playtesting a deck and it made me lose a rank for the season

Just had the same bug : I lost one and won one game in non-ranke Play, and it made me loose 2 ranks.

Yeah.. same thing happening with me

Limited rank decreased in silver after winning a sealed game

Had the same problem today :(

Same problem on my latest 2 matches (around 10 am UTC):
I click a normal "Play" but at the end, my rank changes...

The bug was not there when I played before 9 am UTC, iirc.