Hi !
I had exactly this problem since SU12 and I found yesterday the solution (at least, it worked for me).
Probably not recommended by Asobo but, delete manually all files in the following folders (those are cache files, not deleted by clearing the rolling cache in the game menu):
C:\Program Files (x86)\Steam\steamapps\common\Microsoft Flight Simulator\cache
C:\Users\USERNAME\AppData\Roaming\Microsoft Flight Simulator\PC
C:\Users\USERNAME\AppData\Roaming\Microsoft Flight Simulator\cache
C:\Users\USERNAME\AppData\Roaming\Microsoft Flight Simulator\SceneryCache
C:\Users\USERNAME\AppData\Roaming\Microsoft Flight Simulator\SceneryIndexes
C:\Users\USERNAME\AppData\Roaming\Microsoft Flight Simulator\DCE
C:\Users\USERNAME\AppData\Local\D3DSCache
C:\Users\USERNAME\AppData\Local\NVIDIA\DXCache
C:\Users\USERNAME\AppData\Local\NVIDIA\GLcache
(maybe the same for AMD’s GPU cards)
A310 worked perfectly since I did that yesterday ! No crash on the first loading ^^ (and no more stutters over some sceneries)