Unable to patch Server 2016 clients via SCCM Current Branch

[mkp72]

Here's the scenario:

 

• SCCM Current Branch running on Server 2016
  
• Distribution Point running on Server 2012 R2
  
• 2 SCCM client machines running Server 2012 R2 and Server 2016 added to the same collection and are both in the same boundary group
  

 

I have 2 client servers(2012R2 & 2016) that I am using as client machines to test pushing out windows updates.

My client servers are on the same subnet and in the same boundary group within SCCM. Both see they have updates available. My 2012R2 client sees available patches and downloads them w/out issue. My Server 2016 sees the 5 available patches that I downloaded and deployed in the same Software Update Group and Deployment Package as the 2 dozen 2012R2 patches. The 2016 client stays stuck at "downloading 0%" for days. I left this client server for 2 weeks in this state and just happened to log in today to see it had made it to 3%. I am at a loss as to why this is happening.