P2720DC, not Auto Switching Input

I've recently bought a P2720DC as a second monitor to use with my PC and work laptop while working from home.

The issue I'm seeing is that if it has been used by the PC through the DP connection and the PC is shutdown then the laptop is powered up connected to the USB Type-C port it doesn't switch over without powering the monitor off/on or manually switching the input.

The same occurs when the laptop is powered off and the PC booted up.

Message on the screen says no input detected on whichever port was used last even though I've repeatedly set the input to auto it seems to stick on the last used input and won't look anywhere else.