scaling problem for external UHD monitor

After I installed 10.13.1 a week ago, I am having a problem for my LG UHD monitor.

Scaling function is not working.

Monitor works only for few options :

3840 x 2160 (low resolution)

1920 x 1080

1600 x 900 (low resolution)

1280 x 720

1080P

with 30 hz option only......

Before 10.13.1, my monitor was working fine with other options with 60hz.........this driving me nuts.

I tried to use switchresX, but it crashes whenever restart...

any solution?????????