Very weird FPS fluctuation on SC deck during campaign

Doing mission 2 of the Operation Earnest Will campaign. Spawn in, get a beautiful 50-60fps frame rate with a very crowded deck.

Then things start getting very weird.

As I start up the jet, my fps wavers between 25 and 60fps, usually towards the lower end. Note, this seems to have nothing to do with how many A/C are on the deck - I can get 60fps with 2 hornets, a cat and a chopper, but it then drops to 30fps as I go through the start up.

Erm, any idea what is going on?

The SC deck performance is just weird, and I wonder if some of it is caused by the catapult steam effects. In VR on the deck my FPS fluctuates from 30 to 45. In 2D, with an RTX2070 that used to be an absolute unit with graphics on max, gets knocked into the 20s when looking at a Tomcat doing a cat shot.

The more I play DCS, the more it upsets me. :(

The SC deck performance is just weird, and I wonder if some of it is caused by the catapult steam effects. In VR on the deck my FPS fluctuates from 30 to 45. In 2D, with an RTX2070 that used to be an absolute unit with graphics on max, gets knocked into the 20s when looking at a Tomcat doing a cat shot.

Everything old is new again... remember the terrible performance hit from shell impacts on the ground or water when doing a strafing run, circa 2014? Seriously, this is getting oooooold.