Try changing the refresh rate of your monitor to something lower. To do that, right click on your desktop then click on personalize. Then click display settings at the bottom. This will open up a display settings window. Click on advanced settings then click on the monitor tab. Try lowering the refresh rate to something lower. If that still doesn't allow you to set it at that resolution open the same window and untick the "Hide modes that this monitor cannot display. Be wary though and check the text written just below that as a warning. But since you were able to do that before it might work. Also, in case it doesn't and the monitor doesn't display just wait a few seconds and it will go back to normal. Hope this helps.
