It shouldn't happen every game, unless the games are being played on a bugged map, or with massive armies.
Your connection isn't what causes mismatches, that would cause you to disconnect, at which time you would see the disconnect window pop up(there is nothing wrong with your game if that is the case).
For the time being, I was advise finishing your games withing 20 minutes, which happens to be a decent length for most games, and as for fixing the issue with mismatching, try playing on a different PC with the same files and settings, if that fixes the problem, you've figured out 1 of 2 things; 1. that your main PC is the problem, or 2. it is somebody you're playing with that is causing the mismatch.
Please! Please! try Windscribe free VPN to see if it fixes all of your ZH-Online connection issues!
You shouldn't use the C&C:Online launcher to launch Generals or Zero Hour. If you are playing only those games, you should unhook and uninstall the C&C:Online launcher and install GenTool. When you have done that, you just launch the game from its ordinary shortcut. If you are using the Ultimate Collection, you should install this first; C&C Ultimate Collection Launchers.