So I've run into this issue again and support was not able to get it resolved for me this time. I'm hoping maybe someone else has also run into this.
We had this issue a few months ago and the fix was to remove MS Update KB 2661254 on both the solarwinds server and the vcenter server. That worked last time.
I cannot find that patch on either system but yet the symptom looks the same. I'm not sure that this may be another MS patch or maybe the NPM 10.5 update done in June.
Here is what I see.....
Error while connecting to VMware device - The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel.