I made a test with branch master of project GroupDocs.Total-for-Java-Spring, and another test in demo app, both tests I could print but the document was unformatted.
Please try this web application. The one you are using is no more managed. However, could you please share the demo application that you created and the source file?
I tried the web application as you suggested @Atir_Tahir, but it doesn’t have a print button, even though the print option is enabled in the configuration.yml file. The download option in the viewer project is working, the problem is just the print button.
The demo application that I had used was this, and this is the link that goes direct to my test case.
And this is the screenshot of what I mean when I say that it is not working aptlyprint-pdf-doesnt-work-aptly.png (230.7 KB)
Thank you for sharing the details for this issue. We have created the issue in our internal bug-tracker with ID VIEWERAPP-685. You’ll be notified in case of any updates.