Swift - ZPL, printing correctly on first print when printer is turned on but incorrectly every print after?

I am trying to send two print jobs to the printer . I am trying to print the a label in the correct orientation then using ^POI to print it a second time inverted. This works when the printer has first been turned on but then every print after the first it prints the 2 labels in the same orientation almost ignoring the ^POI.

My ZPL (zplData):

^XA
^LL600
^LS0
^BY2,2,59
^LH0,0
^FT100,400^BQN,2,10^FD##\(attendee!.id)^FS
^A0N,50,50^FO350,240^FD\(name)^FS
^A0N,40,40^FO350,290^FD\(attendee!.company)^FS
^XZ

(zplDataFlip):

^XA
^POI
^LL600
^LS0
^BY2,2,59
^LH0,0
^FT100,400^BQN,2,10^FD##\(attendee!.id)^FS
^A0N,50,50^FO350,240^FD\(name)^FS
^A0N,40,40^FO350,290^FD\(attendee!.company)^FS
^XZ

My Swift to print:

if success! {

      thePrinterConn?.write(zplData.data(using: String.Encoding.utf8), error: errorPtr)

      thePrinterConn?.write(zplDataFlip.data(using: String.Encoding.utf8), error: errorPtr)

}