Microsoft Word Envelopes - Printing a second blank envelope

Question

I'm trying to set a document for the small office I work for where my colleagues can print easily a small list of clients addresses in envelopes. Until now they had a manually formatted word document for each address. (You can imagine, a folder full of words with one address each).

So, I used the right tool, and created a list on Access. I got it working right, but for some reason, it prints a blank envelope between each printed envelope. So I did the process again, created a new document from scratch, and this time it was working. No blank envelopes. I saved the document, opened it again, and the problem occurs again.

The information about this issue is very little in internet, and it doesn't help me at all, but it seems (not sure about it) that it is related to my printer settings. I checked not printing double-sided, but the issue is still there.