Fortnite sudden fps slump, in the air duct at the grotto. Otherwise I always have maximum settings of 144fps with 144hz?

I have never had a drop in fps until yesterday because my pc is very very good. I have an rx5700xt graphics card and play other games with 2k and the highest settings. Nevertheless, it was only once this fps slump… From 144 to 40 very briefly that was when I went into the air shaft who knew about Fortnite should understand me do you think it is because of that? After that I played again without slumps

Maybe this place, this 'scene' is a bit more demanding?