I've never had this issue before but when I important a large folder (43.3gb) that I store on my ssd hard drive premiere pro is very slow to import them (as expected) - however also very slow to open each folder.
Once I've opened each folder it does load faster going back into that folder - like as if it has loaded that content.
However its always annoying and adds extra time to short edits - note it used to open each folder instantly
Here is a video to see exactly what I mean - https://youtu.be/BYGa2ekw294
I've attached images of my pc specs & my premiere pro is the newest possible version & I have cleared caches & maxed my ram for premiere.