Same as https://forums.intel.com/s/feed/0D50P00004a74jOSAQ?language=en_US, I have been experienced this issue.
I use LG 49WL59C-W(5120 x 1440) and it works fine until I update the graphic driver to 184.108.40.20612.
Now my display which has this problem display as 3840 x 2160 and I cannot customize the graphic resolution cause of over max bandwidth.
I guess that this issue is caused by the latest version graphic driver.
I hope that fixed it.