Is there a max search distance for this attribute assistant parameter that would explain why we are getting a "400, Cannot perform query. Invalid query parameters error"? The point feature is 350 ft away from the nearest address in our locator could this be the problem? The documentation doesn't state that the search distance is configurable so I'm not sure what else could be the issue.
Are you able to provide a screenshot or list the parameters you filled in?
From the documentation, I see a few potential error points: