Disconnected when entering a match. Then get into another match when reconnected

I had a problem playing in arena today at
about 3:10pm. My record was 5 wins 1 lose.
Then, I started a new match. My opponent was a
rogue. As soon as I enter the match, I was
disconnected. I’m very sure that my wi-fi is
working really well. I reconnected immediately,
my opponent became a hunter, I lost to the
hunter then my record became 5 wins 3 loses. I
shut down the game and open it again, it told me
that i lost a arena game because I got
disconnected. I wonder how these things
happened, was the rogue cheating or its one of
hearthstone’s bug. If it was internet problem,
why would I met the hunter soon as i
reconnected.

Asia server

Sounds like a variation of this issue:

Won Arena but shows as a loss?
This is usually due to a disconnect while searching for a game or when you cancel your matchmaking. The game places you into a new match instead of reconnecting you into the old one. More details can be found here:
https://us.forums.blizzard.com/en/hearthstone/c/bug-report