Hello mirrorbook,
Depending on how you have it connected, you'll want to make sure the settings on the monitor are set for higher resolutions.
If you're using an HDMI cable to connect the monitor, make sure the monitor signal format is set to "Video/PC"
1. Press the power button to turn off the monitor.
2. Holding MODE down, press the power button for at least two seconds to turn on the monitor.
The “Optional Settings” menu appears.
3. Choose “Signal Selection” from “Optional Settings”, and press ENTER.
4. Choose the input signal to set with the up or down arrow, and press ENTER.
5. Select “Signal Format” with the selected input signal and press ENTER.
6. Switch the signal format with the up or down arrow .
7. Select “Finish” with the up or down arrow .
8. Press ENTER.
If you're using a DisplayPort cable to connect the monitor, make sure the signal bandwidth is set for 4K
1. Press the power button to turn off the monitor.
2. Holding MODE down, press the power button for at least two seconds to turn on the monitor.
The “Optional Settings” menu appears.
3. Choose “Signal Selection” from “Optional Settings”, and press ENTER.
4. Select “DisplayPort” from “Optional Settings”, and press ENTER.
5. Select “Signal Bandwidth”, and press ENTER.
6. Switch the setting with the up or down arrow .
Select “4K” to enable display of 4K signals.
7. Select “Finish” with the up or down arrow .
8. Press ENTER.
User's Manual ColorEdge CG277
If you've confirmed the settings on the monitor are correct and you're still not getting options for higher resolutions, then you'll want to contact the monitor manufacturer for assistance.
Cheers!