Restart everything: Shut down Windows and all your monitors. Then, turn everything on and boot up again. This can often fix your issue. If necessary, roll back driver updates: If your display driver recently updated, it could be causing the issue.
Why is my computer not showing multiple displays?
Follow the steps below to try manually solving through Settings. Click on the Start button to open the Settings window. Under the System menu and in the Display tab, find and press the Detect button under the heading Multiple Displays. Windows 10 should automatically detect and other monitor or display on your device.
How do I get all 3 monitors to display?
How do you connect three monitors to a laptop? First, make sure your laptop graphics card supports three monitors. Then, connect your laptop and monitors to a dock and go to Settings > System > Display. If you don’t see all of the monitors, scroll down to Multiple Displays and select Detect.