Problem: User's external monitors stop working. Reboots don't make a difference. Unplugging / replugging in monitors does nothing. A monitor may say it is not receiving a signal. Monitors used to work fine. The docking station is working fine otherwise--has internet connection, keyboard and mouse work OK.
Solution: Press the Windows Logo + P keys. This brings up the Present mode. Selection was set for PC Screen Only. When changed to Extend both external monitors woke up instantly. Somehow this got changed. Display setting showed extended mode but it wasn't getting video input until this option was run.