/ aside: I don’t understand the -1 here on Tweakers, that system is also as broken as HDMI.
In recent years I have also experienced issues with HDMI that you would not expect for a “standard”. It looks like HTML, where every browser had its own interpretation and websites look different on every browser.
CEC was the first thing I had issues with (Marantz-LG) the following was HDMI 2.0 issues with Audioquest cables between Marantz, Sony TV and Xbox One i.e. video loss … with try and error, rarara, the HDMI 2.0 cables, from a brand (Audioquest) that you would expect to do and that did well in the years before).
Then always the story from pillar to post between the manufacturers of the 2 standards. Finding cables with HDMI 2.1 (Covid as the reason?), Meanwhile, Audioquest now has one, sigh.
No issues with Displayport yet. But they are also not on receivers that I know …