the problem with the textures (Desolate)

what's with the textures in this game? on epic they clearly look (normally that is),but when switching to high for full soap.I have never seen.I want to get a little more fps lowering the texture quality to high or medium,for example.but as already described above,when switching to the same high texture the whole picture turns to mush ultra-low do not understand what.I would understand if it was on the lowest textures (and in modern games this can't remember)...this is a bug anril 4,the game itself or some configuration file correct?