title: Custom cache key missed authentication cache. Need to re-challenge the user to login again
body: <p>Using liberty 18.0.0.1 set up in a collective. I have a custom TAI that creates a subject with a custom cache key. This works out of the box with WAS Classic Cell, but in my collective, when authenticated on one server, and then acessing another server ( in the same collective) a new authentication is forced.</p>
  
  <p>Did some tracing and reason seems to be quite clear:</p>
  
  <pre><code> [4/2/18 18:02:08:659 CEST] 00000803 id=93e3914a com.ibm.ws.security.authentication.AuthenticationException   &lt; &lt;init&gt; Exit  
     com.ibm.ws.security.authentication.AuthenticationException: Custom cache key missed authentication cache. Need to re-challenge the user to login again.
  </code></pre>
  
  <p>Earlier in the trace is shows clearly that the ltpa token is processes ok, the custom key is retrieved, but</p>
  
  <pre><code>[4/2/18 18:02:08:659 CEST] 00000803 id=aea8ae88 com.ibm.ws.security.token.ltpa.internal.LTPATokenService     &lt; recreateTokenFromBytes Exit  
    /VRnC blabla &lt;the rest removed by me ..&gt;
   [4/2/18 18:02:08:659 CEST] 00000803 id=         com.ibm.ws.security.token.internal.TokenManagerImpl          3 Successfully recreated token using token service com.ibm.ws.security.token.ltpa.internal.LTPATokenService@aea8ae88.
  </code></pre>
  
  <p>So why is the authentication cache from server1 not visible for server2 ?</p>
  
  <p>/bwa</p>