Search filter for the user management works with a full text search and not only a search like startsWith()
The current user management has got a very restricted filter search, where you only can apply a search word, which starts a filter with startsWith() instead of a full text search. (containing the search word)
We agree this would be a good improvement to the API for Cumulocity IoT and will consider it for inclusion in a future release.
Regards, Jane.