Cannot copy multiple whole staves with CC data

As I am recovering lost data from old backup files, I am copying everything with CC data from one grouped instrument in one file to multiple instrument staves in another file. However, I couldn’t find a way.

Source:

Destination:

That is, I want to copy from Trumpet (2 staves) into Trumpet 1 (1 staff) and Trumpet 2 (1 staff).

I tried many ways:

  1. Ctrl-C then Ctrl-V: All notes, lines and dynamics are copied. CC data copied up to bar 6 only. Besides, the first staff from the source would be unexpectedly pasted into 2nd staff in destination.
  2. According to this post, navigate to the specific layout, select system tracks and Ctrl-C, then Ctrl-V: Everything including all CC data of 1st staff are copied. But no way to copy the 2nd staff, even if I right click and remove the 1st staff.
  3. Paste special → Explode: All CC data are lost.
  4. Alt-click: Only one bar rest is pasted.
  5. Alt-N: Similar to 1. Some CC data are lost.
  6. I tried turning off “Link dynamics and slurs to existing items when pasting” in Preferences, and there seems to be no difference.
  7. And “Include MIDI CC, pitch bend and dynamics from Key Editor when copying music” in Preferences is checked.

May I have an advise on how to copy everything with CC data from one grouped instrument in one file to multiple instrument staves in another file? Thanks in advance.