While troubleshooting what I thought was a DisplayPort issue with my Samsung Odyssey G8, I switched to HDMI using the cable marked “HDMI 2.1,” which matches my display’s spec. The panel lit up, the resolution was correct, and at first glance, nothing seemed wrong, but when I noticed the refresh rate was capped well below the panel’s advertised 4K 240Hz spec, I knew the cable was at fault. Upon inspecting the rest of my HDMI cable collection, I noticed most cables I own aren’t capable of the top-end of HDMI 2.1 spec, despite the fact that they came bundled with HDMI 2.1-capable devices.