Yes, I have had the same issue. The fix isn't obvious, but it is certainly easy.
Check Extension Manager/Manage for the Community Builder Admin menu module. If it is not there, then you will have to reinstall. If it is there, make sure it is enabled.
Now head over to Module Manager and select the Administrator box and look for Community Builder Admin menu module. Not there? Then you will have to create an new instance of it. Click New, select Community Builder Admin menu from the list, choose Position:Menu, Display Mode:Drop-Down Menu and complete the installation. That's it! You should now see it in the top admin menu bar.
Not sure why this happens, but it can be frustrating!