sorry..I think then the problem is to another place..
I have again scanned the all GIGA GM sounds patch slot and I get the all correct sounds.
I can aslo switch engine and return back and all play correct.
On my qsampler also will load the correct sounds too.
MAY you try to use again my original MS-02-instruments-1.lscp file and restart?
I can not stress my developer IF I can not reproduce your same bug.

Give some others MS user that have tested my last patch? May I know if the sounds match to the slots?