Riparia ocean lagging at cinematic render

fps drop immidietly after u look at the certain part of the ocean

so when im near the ocean and i look at it my fps drops to 37 but if i look at the rest of the map i have 75-85 fps and fps drops so fast like right after i look at the specific part of the ocean

i except too see stable FPS no matter at what part of the map i look