Hi all,
Every matchmaking game i start will end after 2 min with a Victory for me and chat saying:
[ALL]Blizzard: Warnung: Game Desync Detected by player [randombattletag#0000]
In loading screen i got a black minimap in the middle. Custom games work FLAWLESS. Map appears, game doesnt desync.
I tried reforged and classic graphics.
I did a router update.
i did an ipconfig/renew and DNS flush
I can´t play the game since November, worked before this patch.
If i create a custom match i see the minimap in menu how it should be.
If i open the mappool in versus mode all minimaps are black.
I guess this is the problem but i dont know why.
I would really like to know how to fix it, so i can rebuy Reforged 
I have exactly the same problem. Did you or someone else found a solution for this issue?
This was a major major issue in the first months after release, allowing people to accrue icons in a matter of weeks due to everyone just dropping out of games. Blizzard has struggled in fixing this and for a long time couldn’t get this issue resolved properly so they just coded the alert message away so it appears more as a random drop than a desync, shifting perspective that it could be the internet from the user rather than the bad coding of the game.
However, this is mostly gone now and happens very very rarely; in which case it probably is the internet of the user. Does it still tell you desync or does it simply boot you to the score screen? If the latter it is probably a package loss. For reasons unknown blizzard removed the grace period and did not add a reconnect function for the game. A package loss from your internet service provider is very likely to cause ‘instant’ boots to the score screen.
It is unsure why blizzard isn’t up to standards with the year 2000 but for now the only way to fix it is to improve your internet. Or wait till blizzard gets this game together but frankly; we are still missing a smooth opening menu, profiles or even the link to our classic accounts. I think that waiting for blizzard is kinda like not buying a lottery ticket and still hoping you win the jack pot.