Getting Invalid path to authentication servlet.: / when try to login to /ccm

I have seen several similar posts but none seem to answer the question, or address my circumstances. Or perhaps I just did not understand the answers correctly.   So I am posting again with more details.

I am running Jazz, RTC all on iseries  with websphere, ,  not using LDAP, 
User is in the correct user profile group  (JAZZADMINS),   User in JTS with active licenses. 
Running RTC  6.0,  WAS 8.5.5.   Was also getting on prior versions of RTC. .
Have tried both Chrome and Firefox with same results.
Tried the keep hitting 'refresh'  suggestion -  did not help

the URL we are using was working before, and has been verified as correct.  Occasionally it  does work correctly.
 
Enter the correct URL  server:port/ccm  ,  get the JAZZ login page,  enter credentials,  then get the error.  with the url listed as <server:port>/ccm/auth/
Can log in correctly if go to <server:port>/jts   and then navigate to CCM.
If open the web UI from the Eclipse client (using same URL)  it appears to always work.

Does anyone have any specific solution to this?  It is particularly annoying to not be able to go directly to the CCM web UI.