1440p missing high res on Display resolutions
 

I've got a Mac M1, and if I plug my display directly to my Mac, I can see 2560 x 1440 in retina solution (High Res). However, with DisplayLink, I can't see high resolution for that size. I've got 1.6.1 software version

This is a sorely missed feature in the macOS DisplayLink driver.

However, there is a workaround. Take a look at the project "BetterDummy": https://github.com/waydabber/BetterDummy

This will give you HiDPI even if MacOS doesn't support it.

You get the best performance when using "FullScreen Stream".

Not OP, but I'm having the same problem with a secondary 3440x1440 monitor where the highest resolution I see is 2560x1440.

I've downloaded BetterDummy and created a dummy screen with a resolution of 3440x1440 and associated my secondary monitor to it. The resolution still doesn't seem to be correct and I lose a lot of features such as snapping to the entire screen, menu bars, etc and the screen appears fuzzy.

Is this the correct way to do it? I also can't seem to find the option for the FullScreen stream?

FullScreen Stream is currently only availble in the public Beta releases.

In my DisplayLink setup, the rendering result is better with "FullScreen Stream" than with "Mirroring". It is not identical to a direct DisplayPort connection (via USB-C adapter), but at least on the normal desktop it is hardly distinguishable.