[Windows Central Question]

I have two windows 10 PC's and two different Dell monitors. Both monitors interfere with the Wi-Fi on the PC. The setups I have are:

1. Surface Pro 4, Dell P2415Q monitor (certified for Windows 10), Display Port to Mini DP cable, Windows 10 came on the SP4 and is fully updated.
2. Desktop from MESH Computers, Dell U2414H monitor (certified for Windows 10), HDMI to HDMI cable, PC was originally running Windows 7 and was upgraded to Win10 which is fully updated. This setup worked fine until 26th December when I took a Win10 update and it's now no longer working.

The behaviour I see is as follows:

1. on my SP4, if I don't have the monitor connected I can access Wi-Fi. As soon as I plug in the monitor in the MiniDP the internet access is lost (connection remains in place). If I unplug the monitor then the internet starts working again.
2. on my desktop, if I have the Dell monitor plugged in then I am unable to connect to the Wi-Fi network. If I plug in an old monitor (VGI to VGI) then the wireless starts working again.

Microsoft currently suggest it's a cable issue but: the cable on the desktop has worked for weeks until 26/12; can't see why this is happening on two entirely different setups.

Anyone else seeing this or any ideas?

Thanks.