OS Catalina HDMI not working, mini-display work-around 'blocking' wifi.

Hi there,

I've run into a common problem it seems when upgrading to Catalina, my HDMI port connecting to an external monitor no longer works. My setup is:

MBP retina mid-2014 2.6GHz and 8G . Screen is an LG L192WS from 2007. They're connected by VGA-VGA, with an HDMI adaptor.

I also have an HDMI to Mini-display, so as a workaround I tacked that onto the HDMI adaptor and it works thankfully. However, as soon as I plug it in my wifi stops working, and then starts working as soon as I unplug the screen. Have heard this is because it interferes with the wifi frequency, and tried wrapping the cord in tin-foil (old wives tale which didn't work). The mini-display port slightly further from the back doesn't seem to work, and there's nothing on the other side except the HDMI.

I have reset the NVRAM, but that has done nothing.