Anyone else getting blank envelopes?

I am using LibreOffice 7.0.1.2 on a Windows 10 ver. 2004 machine. When I try to print envelopes they come out blank. Tried it on a different machine using the same version of Libre but was a Windows 8.1 and the same thing happened. Did not have this problem with LibreOffice 6.1 but not allowed to go back to that version.

Does the tip given in question 267440 help?