[2020] For every few seconds, the game freeze a moment

Is this just in one particular campaign then? Perhaps one where someone owns a large chunk of the map, and there are armies everywhere?

If so i's probably the same as this report:

Constant stutter every 1.5 second

Short summary of your issue Constant stutter every 1.5 second Game Version 1.1.2 What OS are you playing on? Windows What platform are you using? Steam Do you have mods enabled? No Have you tried verifying your game files (Steam only)? Yes... forum.paradoxplaza.com
Please follow that through to the Bug reports thread and attach your save there too for QA to look into. Thanks, and sorry for that problem!