WDM 4.7.2 not deploying packages

WDM 4.7.2 not deploying packages

Been banging my head against the wall on this and couldn't find any other relevant threads.

I have a WDM 4.7.2 server that, when I deploy a package to a device, 1 of 2 things happens:

1. The package distro status moves to "In-Progress" but nothing actually occurs at the client
2. The package distro does not move past "Scheduled"

The lock user screen does not appear on the device.

Here is what I have done so far:

Confirmed FTP and HTTP in good working order on WDM server
Checked that anonymous connections are allowed via HTTP and changed the default IUSER password back to the default
Checked that the default user for the FTP site can log in
Checked FTP logs - no indication of attempts to connect
Rebooted clients
Put clients on a network with no firewall restrictions
No errors in HTTPERR.log
Run Diagnostic Report with the result of no failures
Checked scheduling preferences and made sure that Time-Bound rollout is enabled
Ensured that I can reboot clients and view/update device information

This happened all of a sudden late last week while I was testing a new package for deployment. I had run the package 20-30 times with minor changes between each.

Any ideas??