Forticlient 4.0.23 web client connection oscillates between up and down

I've had the 4.0.23 client running for a few months with IE on Win10 - no issues.  Earlier this week, when I hit 'Connect', the status would oscillate between 'up' and 'down', spending about 1 or 2 seconds in each state, never actually staying 'up'.  This would continue until I closed the page.  Watching the forissl network adapter, I could see it was 'connecting', but never succeeds.  Again, it spends about 1 or 2 seconds in that state before showing 'disconnected'.  

My company regularly updates Windows software so I suspect something installed that changed the configuration.  

I found the following thread:  http://kb.fortinet.com/kb/documentLink.do?externalID=FD36630

Even though my symptoms are different, applying the outlined steps solved my issue, but I'm not sure why. 

Have others seen this behavior?  What did you do to solve it?

Thanks.