This format prints 50 copies of an identical label. If they were meant to carry serial numbers, ^SN is missing.
Add ^SN for serialised output, or reduce ^PQ to 1.
^XA^PQ50^FO50,50^A0N,30,30^FDBOX^FS^XZ
^PQ with quantity greater than 1 and no ^SN anywhere in the format.
Neither ^PW nor ^LL is set. Both fall back to a value stored in the individual printer, not to a value in the spec — so the same ZPL prints differently on two printers of the same model.
Set ^PW and ^LL explicitly in every format.
This format prints 50 copies of an identical label. If they were meant to carry serial numbers, ^SN is missing.
Add ^SN for serialised output, or reduce ^PQ to 1.