Getting this Lag


I have some problem with this game on PC , sometimes the game lagging a lot like almost freezing for about 10-20 seconds after the game loading the map into drop ship as hunter and also sometimes with monster i guess it’s up to the map i’m playing , if the map have some weather like snow or rain or something i will get this lagging but after that first 10-20 seconds lag after that there’s no lag at all which is really weird and really annoying and i already put the graphics to low so… anyway to fix this ?