Unfortunately, # is not a valid character in the query field, and will be removed from the search query (silently on Google’s end). Therefore, the result is that ALL events will be returned, as your query is now considered “empty”.
Try using another phrase as the search query.
For more information on how to use this freeform query field and what it searches, see Events: list | Google Calendar | Google for Developers
Hope this helps! If you are still having trouble, please provide more details.
— @samliew