I've noticed a save games bug where the GOG Galaxy client fails to properly sync save games.

(I delete local save games and then later the GOG Galaxy client re-downloads them from the cloud)

The client then says "cloud sync failed".

The save games folder is ballooning over 1.1 GB.

Are you on Windows, and do you have any [software] firewalls turned on? make sure that lsass.exe is allowed full access both out and in, or it wont sync any saves