U2412M, not detected by second PC

Hi,

I have a U2412M that works without a hitch with my desktop computer (connected via Nvidia HDMI to U2412M DVI cable). 

But every time I try connecting the U2412M to another computer (I tried 3 different laptops), they go undetected! This seemingly happened overnight, i.e. it used to be that it worked without a problem.

All computers are running Windows 10.

I also tried a DisplayPort to HDMI cable.

I tried to reset the screens factory settings (via screen menu).

Please help.