I always have dynamic lights off, and I still get the frame drops on Eygpt map, I did notice when I looked at it the past that those white things are network replicated for some reason, I'm under the impression that is not necessary for stuff like
that, and the frame drops happen every so often(several times a minute) like something builds up and gets to a state where it causes the heavy fps dip for a second or so and performance is somewhat normal for a little while and it repeats.
It's a common problem on that map I hear players complain about, I've had 5-6 different pcs the last year(various states) or so and the problem is consistent no matter the gpu or cpu. CPUS: I5-2400(2 different ones), I7 2700k, i5-3470, I7 6700k, Ryzen 5600, GPUS: GT710, GTX 970, GT 1030, GTX 1050ti, and an AMD gpu I had for a few days that I can't remember the model as I re-sold it because I couldn't get 144hz out of it.