Waze uses a third party forum software called phpBB to drive its forums.
This software has a feature that attempts to keep large searches from slowing down the forums for everyone. Unfortunately, this feature causes words that are commonly used to not be searchable.
A workaround for this is to use Google's site specific search to look for posts.
From the Google page, search for:
SITE:WWW.WAZE.COM/FORUM <your search term(s) here>
For example, to search for the phrase: no permissions
SITE:WWW.WAZE.COM/FORUM "no permissions"
Note that this workaround has a limitation that Google must have already indexed the topics being searched. Therefore, newer topics may not be available at the time of your search.