24.1 beta 3: Saving MIDI scores issue

[Xaos]

If I drag and drop a single channel midi file into the piano roll, like the attached MIDI file (Original), if I then save it as a MIDI score file (After), the next time I open it, it will ask me which channels I want to import the information from.

A#maj9 (Original).mid

A#maj9 (After).mid

That is to say that by saving it as a MIDI score, instead of a single channel, it has saved it as a standard 16-channel file.
This doesn't make any sense.
In previous versions, it worked correctly, that is to say that it saved the information of only one channel.
I've been looking in the settings to see if it's possible to adjust the MIDI score files, but I haven't found anything.

[reflex]

I'll check what's changed. EDIT: it's not the ...

[JLAB]

That's... Quite unfortunate.