Does the U2421HE have a built-in KVM switch, or otherwise able to perform a similar function?
If yes, would the following arrangement work?
#1) Laptop to U2421HE via DP, Desktop to U2421HE via HDMI, Keyboard to U2421HE via USB, Mouse to U2421HE via USB.
The online U2421HE User's Guide does not show a KVM USB Selection option in the Menu. Dell-Admin