FPS fluctuations and short stills Fortnite?

Since last I have always strong FPS fluctuations and the FPS are synonymous not as high as, for example, 3 months ago… The next problem is that I always have short 1-2 seconds when playing still images. My PC is not bad at all and should be enough for a game like Fortnite (i5 and GTX 1060) how can I solve this problem?

It could be because of the new season, because the servers get a lot of new data and sometimes it lays…