Add CT-SCv3020 to SCVMM Fabric - SSL Error

I am having a really hard time getting our new Compellent Device added to the SCVMM Fabric.  I have SCVMM 2012R2 and 2016 on separate management servers. 

Storage Manager is installed on a separate server (Unisphere Central version 18.1.10.171).  Windows Firewalls are all off.

I have finally managed to get the Self-Signed certificate off the website (which runs on port 3033) - and installed in on my SCVMM 2016 Server.  The website now opens properly, without a Certificate Error.

However when I try to add it to the Fabric (both with ssl on/off) it fails:

Could not retrieve a certificate from the (FQDN of Storage Management server) because of the error: The request was aborted: Could not create SSL/TLS secure channel.

Specify a valid server name and port.

ID: 20909
Details: Unknown error (0x194)

What am I missing? 

We have an internal CA, so I tried to create a certificate for it - but that is not working either.