PS4 Pro strange graphics/crash issue only in safe mode and HDR

Not seemingly a classic Pro/HDR problem.

I have a PS4 Pro that will boot to menu fine, play older non-HDR games fine, and DVDs are perfect also e.g. FallOut 4, FIFA 16, FIFA 17.

However, I put FIFA 19 in and immediately on launch (as it seeks to go in to HDR mode) the graphics broke up and glitch, and the game won’t get past the loading screen and will crash (back to the PS4 o/s asking whether to report the fault or not) after a minute of not being able to run.

I went in to Safe Mode to reinstall the system software from scratch, and noticed graphics problems in Safe Mode straight away. It’s a jumpy screen and there is a phantom broken line near the bottom of screen.

Maybe it is an HDR problem, but the PS Menu is perfect and non-HDR games run perfect, and there is this graphics trouble in Safe Mode. And another glaring issue in Safe Mode, when going ahead in Safe Mode, the 8 options are there (I used option 7 for reinstall), but they are not all visible. , missing on every other line.

I’ve tried multiple hi-speed compliant HDMI cables and the TV switches over correctly to HDR when required i.e. when FIFA 19 starts to launch.

I’m thinking maybe the HDMI circuit/port/connections/components/something is shorted/broken. An unwanted short to ground maybe?

Anyone seen this or know where to start? I guess I should be getting the multimeter out and checking diodes/components around the HDMI area/port.

Thanks in advance for any thoughts / help