Check for exact spelling. Uppercase/Lowercase does matter.
open endpointuser in LDAPBrowser and compare their attributes to the ones you've set in the group mapping list - that will tell you why they are not getting mapped.
Thanks for all your help.
I downloaded LDAPbrowser and managed to fix the problem,
The issue was:
1. Upper case and lower case was not correct.
2. Search list was empty.