Thank you for confirming, Allan.
As you are likely already aware, this is a common problem with this model, which had some design and quality problems that manifest in a high failure rate of the hdmi/processing circuitry.
The one thing you can try is a microprocessor reset:
Power off, then while holding the enter button, power back on
It will show RESET NO on the amp display,
and you'll use the Preset <> buttons to highlight reset,
press enter so RESET ? shows, then enter again to confirm.
If still no change, it would unfortunately confirm a hardware fault, which again is a known issue, and not uncommon to see even just from normal age related wear and tear on these units. This is a 2012 model, so it is nearly at the end of its service life at this point anyway. This is something that would require significant repairs to correct, replacing the hdmi board, which will run you about $600+ in parts and labor. For an amp of this age and with this known fault (which would likely fail again even after repair), it isn't wirht the investment when you could get a brand new and updated model with a fresh warranty for the same price range.
The alternative to repair/replacement would be to keep the amp as-is, routing all your hdmi devices directly to the display, then using separate optical connections from the display (or each device) back to the pioneer for audio.
I can recommend a local repair shop, or help with replacement recommendations if you prefer.
Best regards, ***** ***** for the news,