Yes is just the game, I can easily kill the process in the task manager an restart it but after I reload the game and start playing the again the same problems happens again after some time
I was using the map improvement mod while I was playing, and started another save as Austria without any mods and I get the same problem both in the 1.29 update
It's not game breaking, just really annoying, I don't have the same problem with other paradox games like ck2.