This ^FX comment does not end where it should. A caret inside the comment restarts parsing there; a ^FX with no ^FS swallows every command until one arrives. Either way the label gains content nobody wrote.
Keep ^ and ~ out of comments, and close every ^FX with ^FS.
^XA^FXnet ^ gross weight^FS^FO50,50^A0N,30,30^FDX^FS^XZ
A ^FX comment whose text contains ^ or ~, or a ^FX not terminated by ^FS.
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 ^FX comment does not end where it should. A caret inside the comment restarts parsing there; a ^FX with no ^FS swallows every command until one arrives. Either way the label gains content nobody wrote.
Keep ^ and ~ out of comments, and close every ^FX with ^FS.