Attachment icon when printing the invoice

I’m getting the paperclip icon (file attachment) at the end the invoice, even when there is no attachment to it.
It doesn’t appear when I generate a PDF, only when I print it. I’m using custom themes if it matters.

try printing with any default themes so that we can rule out the possibility of custom themes causing the issue.

It doesn’t show up in the default theme. So, something is wrong with my theme. Got it.
Is there way to effectively create a good theme?

Custom themes are users’ own responsibility. If you don’t have the necessary skills, hire a local programmer who can code in Liquid. Most competent web developers should be able to do this for you.