Fallout 4 - frame drops

[MINIaFUZE]

I know it's a somewhat old game but i'm currently playing through fallout 4 on ultra settings. In some areas, my frame rate drops from 60 to about 45. I'm running it on a GTX 1660 ti and an i7-9750H. I installed MSI afterburner to see if I needed to reduce my settings but according to it, my GPU is only ever at about 60-70% usage and my CPU 40-50%. My temps are never above 75 degrees when playing it, so I don't think it's a thermal issue. Turning the settings down doesn't seem to help so i'm wondering if it's just Bethesda? Has anyone else experienced a similar issue?

Thanks 

[Bacon soup]

yea its just the game. I have a 5700XT and my FPS on ultra go between 75 FPS to over 200FPS. 

[MINIaFUZE]

Thanks