As the title says, there was a new update for DCS yesterday, some updates on the Normandy map, and a lot of fixes for the F/A-18.
I ran into this suggestion while reading the DCS forum, I think it might have helped a bit:
Chaps,
I’m conscious that it was previously identified that the FXO and metashaders folders within our Saved Games folder were potentially causing some stutters due to the game engine addressing an ever increasing list of files. The easy solution being to delete the folders, which are then re-created by the game, but this time empty.
With the latest update, probably worth deleting them again.
Note that this will actually increase the load times on the first new load, but post that, should help.
https://forums.eagle.ru/showthread.php?t=204621
Then it might be a good idea to open up a mission or two offline just to give DCS a chance to update whatever it needs to before going online.