[Edit] Misunderstood, you're creating, not saving the DMG. I ran a quick test, am able to replicate the issue. Created a blank file, and created an empty folder, both with *.PKG suffix. Disk Utility ignores both. TBH whenever I create a DMG from a PKG, I always create an enclosing folder first.

$ touch ~/Desktop/TRASHME/testFile,pkg

$ mkdir ~/Desktop/TRASHME/testFolder.pkg

$ ls -lF ~/Desktop/TRASHME/

total 0

-rw-r--r--  1 donmontalvo  staff   0 Jul 22 21:59 testFile,pkg

drwxr-xr-x  2 donmontalvo  staff  68 Jul 22 21:59 testFolder.pkg/

$

Disk Utility ignores both:

@jpadilla Are you trying to create a .dmg of a .pkg so you can deploy it with Jamf Pro? Can you not just deploy the .pkg file itself? If you really need the .pkg encapsulated in a .dmg, put the .pkg into a folder, the select that folder as the folder to create the .dmg from rather than the .pkg file itself. Or use the Composer app (one of the tools in the Casper Suite folder) to create the .dmg

@donmontalvo @sdagley Thank You! Enclosing in folder worked for me.