Print to PDF, barcode problem

hello,

I'm troubling with printing using fantastic Nintex form's tool (Print to PDF).

unfortunately, just showing me an alt text (cannot showing barcode on paper). 

example linear barcode image url: /_layouts/15/barcodeimagefromitem.aspx?ID=1&list=875c0e2e-fac7-4439-8248-0d705fc206fa

and I used image in nintex form, by choosing source: barcode ({ItemProperty:_dlc_BarcodePreview})

it's work, and show in preview. just after converting and creating pdf, barcode not show!

preview mode:

print mode:

thanks in advanced.