MacBook Pro suddenly not connecting to HDMI I have a MacBook Pro and regularly connect it to a Samsung TV via HDMI.

Suddenly, it has stopped working - when I connect the cable the screen looks like it is about to share, then comes back.
To my knowledge, I did not run a software update. 

I have tried 2 different cables (one with, one without USB-C multi adaptor [not apple], both which worked in the past
(and the multi adaptor is recognised when external hardrives plugged in instead) . Tried both thunderbolt ports.

This is clearly a Mac issue. I tried resetting the NVRAM - all that happens is the screen intermittently turns on and off whilst I hold down the keys (is this correct?)

Anyone know how I could fix this issue?? 
Many thanks!
In System Preferences > Displays > Arrangement > turn Mirroring on or off, whichever it wasn't set at.

Then resetting the NVRAM again https://support.apple.com/en-us/HT204063

and the last opportunity is to change the Mirroring back to what is was before and reset after that the NVRAM again.

I hope I could help you..