Sorting Input does not show in output mkv file

Pop!_OS 22.04 LTS
MKVToolNix GUI, v 86.0 “Winter,” 64-bit, DEB and Flatpak

I loaded a dozen mp4 files into the Input section and sorted them using CTRL-arrow, but the output mkv file is never in the same order. I Appended them one-at-a-time in the Input Screen, still they persist to be out of order. I Added the files instead of Appending them, ordered them, but still they are out of order in the mkv file. What have I missed?

You need to re-order the tracks in order to affect the order of tracks in the resulting file, not the source files.

Thanks, that was what I missed.