"Fake" HDMI 2.1
Some manufacturers have started claiming that their TVs support HDMI 2.1 while only supporting a few features of HDMI 2.1, or in some cases, none at all. As reported by TFT Central, this is due to a change by the HDMI licensing board, which essentially deprecates the HDMI 2.0 standard in favor of HDMI 2.1. With this change, since HDMI 2.1 is fully backward compatible with HDMI 2.0, manufacturers can claim that their devices meet the HDMI 2.1 specifications without actually supporting anything new.
This is, of course, highly confusing for consumers. It's no longer possible to infer which features a device supports simply by the HDMI port specification; we instead have to dig deeper and hope that the manufacturer is transparent about which features their display supports. In our reviews, we only consider a device to be "HDMI 2.1 Class" if it supports bandwidth beyond the limitations of HDMI 2.0. Since features like eARC and VRR don't require any extra bandwidth, if a TV only supports those features, we consider it HDMI 2.0, even if the official certification has been retired.
This also applies to monitors. We only consider a monitor to have HDMI 2.1 ports if those ports support higher bandwidth formats over HDMI. For example, if a monitor supports 4k @ 60Hz with a 10-bit, 4:4:4 signal, it's HDMI 2.1. HDMI 2.1 ports can support different maximum bandwidths, but as long as they support more than the 18Gbps limit of HDMI 2.0, we consider them HDMI 2.1 ports.