I had the same problem with my HDMI Sony Bravia TV but it would display on my PC Screen. Kept saying "unsupported signal" or "check the signal and try again". I made a YouTube video about it to help anyone else with the same issue.
https://www.youtube.com/watch?v=OF-dfJEvYrY
If you want it to display, you have to edit the config.txt file.
Change the line:
dtoverlay=vc4-kms-v3d,cma-256
to
dtoverlay=vc4-fkms-v3d,cma-256
The rest is optional.
hdmi_group=1
hdmi_mode=16
hdmi_cvt=1920 1080 60 6 0 0 0
And it should display on your TV screen.
Hope it works!