When I switch Input Source from HDMI 1 to HDMI 2, then back to HDMI 1, the S2721QS says there is no signal from the computer on HDMI 1. 

The computer still says the Input is connected on HDMI 1, it is only the S2721QS that says there is no signal. 

I have tried turning off all power saving option on the PC and in the S2721QS settings. I have also turned off power saving options in the BIOS to ensure the port isn't being switched off to save power. 

In order to make it work I have to choose the 'Disconnect this display' option in Display Settings, then instantly revert the change when prompted and the S2721QS picks up the signal again. 

I have tested the cables, they are all working fine. 

How can I make sure the S2721QS still recognises the signal from HDMI 1 when switched to HDMI 2? It makes the option of switching inputs pretty useless if the input has to be re-connected when switching back anyway. 

Thanks.