hmm... based on your description (or one part of it) this should NOT be it but just for the sake of checking it out...
1) Save As so you can return to the original project if you want
2) Break open the "Take Lanes" on the original MIDI track (you'll see the individual clips for all the drum elements your recorded)
3) Select all the clips in all the take lanes (and unlock any clips you have locked)
4) Right click on one of the clips and select "Bounce to Clips" (this will combine all the clips into a single clip)
5) Drag that newly created clip into the desired track
What I'm thinking MAY have happened is you copied the parent track into the new track and somehow it only selected the hi hat clip.
Of course if you SEE the notes of the other parts that would not make sense but you may be seeing something other than what is actually going on.
Give it a go and let us know if it worked.