A MacBook Air 2014 outfitted with Big Sur and a single 2560X1440 (2K) monitor via HDMI. Apple indicates:
Intel HD Graphics 5000 Dual display and video mirroring: Simultaneously supports full native resolution on the built-in display and up to 2560 by 1600 pixels on an external display, both at millions of colors Thunderbolt digital video output
Resolution is output at 1080. How does one command the machine to provide a 2560X1440 resolution option?
Is there a test that can be performed to eliminate the cable as the bottleneck?