Had the same problem and debugged the generated FM.It uses the AT NEW statement, so the field you want to group by must be the first field in the row structure or you have to make sure that the fields left of your group field don't change.
See code below, copy to editor and print it on your Zebra.Look at Zebra Programming Guide for explanations of commands.~SD15~TA000^XA^PW320^LL200^PON^PR2,2^PMN^MNY^LS0^MTD^XZ^XA^JUS^XZ
We have this problem too, an other application sends ^pw to the Zebra, then the labelsize doesn't fit the Adobelabels anymore and the whole output is shifted.Our workaround is a ZPL-File we "print" on those devices before we deliver the printer to th...