Performance around Stockholm, Sweden

I’m not sure whats going on, but when making a flight from let’s say Arlanda (ESSA) or Bromma (ESSB) there is a LOT of stutter (as well as lower fps) going on. It’s sometimes really bad. I first though it was because badly optimized Scenario (ESSB) I used, but that was not the case I guess; even with the scenario uninstalled, the performance around Stockholm is plain bad. I just wanna hear with you fellow pilots, If you have noticed the same? If so, what is causing this? Is Stockholm (with surroundings) badly optimized or something? Even LAX is more smooth to me!