Yesterday the German sound expert site Heise announced that it discovered a bug in the HDMI 2.1 interface, which can cause black screens with a specific hardware configuration.
HDMI 2.1 fails with 4K 120Hz outputs on RTX 30 and Xbox Series X GPUs


The problem lies with Panasonic AV chips, which are used by Denon, Marantz and Yamaha HDMI 2.1 AV receivers. This chipset experiences a crash when connecting one of NVIDIA’s newer GPUs, the RTX 30 series, or an Xbox Series X, which results in a black screen.
Black screen reportedly occurs when these devices are connected at 4K / 120Hz HDR and 8K / 60Hz HDR resolutions on Panasonic’s HDMI 2.1 chipsets.
Fortunately the problem appears to be hardware specific, other devices are not having this problem, such as the PlayStation 5 . For now, the solution is to lower the resolution and / or refresh rate to HDMI 2.0b (4K 60Hz) standards. Another solution is to connect the AV receiver eARC HDMI port of the TV and connect the affected device to the TV. In this way, the AV receiver only takes care of processing the audio while the television takes care of everything else.


Needless to say, this represents a big problem for all manufacturers who planned to use the Panasonic chipset, so it must be resolved urgently.
For its part, the Audioholics site got in touch with Sound United and Yamaha, who gave their answers and sensed that this problem could be solved in the near future through a software update.
Simply put, the momentary solution is to use the 4K / 60Hz setting until the issue is formally resolved. Luckily this only affects 4K / 120Hz monitors, which are pretty rare today.