Weird static issue

So I’ve had 3 ps4’s come in that have had an issue where the tv has made static across the screen, but only in safe mode.

It crackels and goes all staticy across the screen (like when you have a broken HDMI port) but the second the ps4 software loads up, everything is suddenly fine.

There’s absolutely no static when its not in safe mode, i assume its running low res in safe mode, but can’t understand why it goes crazy. I get about 2 seconds of a clear screen for me to go through the install options and then have to wait 10 seconds for it to clear again.

Any ideas?
Done this one a ps4 that i just replaced the port on and 2 that have had still pretty much new ports installed.