“This protocol converter is specified to handle 1080p (aka 1920x1080). It probably does. I got it to test on a monitor with a native resolution of 1280x1024. In practice, the monitor worked fine when connected to a Pi4B, but the resolution came up as 1024x768.
So, while it works at less than 1080p resolution, it is clear that the converter doesn't faithfully recognize all EDID values.”