If you mean HM:WL and HM:AWL then I got the exact same problem as soon as the lights in the houses turn on.
By playing around with the graphic settings I found out that disabling Fast Mipmaps in the graphic settings somewhat alleviated the problem bumping framerate up to atleast 10-12 when it was at 1 FPS before
At least on DX11 this worked... Just tried it on OpenGL and nothing changed but OpenGL has less FPS all over but still higher than DX11 at night with those Fast Mipmaps
By playing around with the graphic settings I found out that disabling Fast Mipmaps in the graphic settings somewhat alleviated the problem bumping framerate up to atleast 10-12 when it was at 1 FPS before
At least on DX11 this worked... Just tried it on OpenGL and nothing changed but OpenGL has less FPS all over but still higher than DX11 at night with those Fast Mipmaps