Strange issue in campaign map

#820075

So a weird thing happens every time I play Warhammer III. So I have a very good PC, with i9 processor and an rtx 3080. When I start a campaign most often it will run smoothly with everything set to ultra and extreme at 4k at around 35- 45 fps. In battles I have again always very good fps and even better than campaign map. After a battle though, after the loading of the campaign map finishes my fps drop at around 10-15 fps, it will not happen always but when it does it will go back to normal only if it makes something the game load, for example if I change my settings and it will load the new ones some times it will get back to normal, or maybe after a battle. But again that is not always the case as some times it will stay at 15 fps until I reboot the game. Battles are never affected by this phenomenon, they will always run smoothly. It happens with both the gpu I have now and the previous rtx 2070 super I had and after some monitoring I did the system runs perfectly fine. What causes these drops and what should I do?