IMHO, it’s unreasonable to expect one to perform such a common search designed to narrow down source files at the database search level from within the search inspector. Who would manually click through potentially thousands of files one by one, repeating a basic search in the search inspector just because the database search is broken?
The manual says nothing to indicate that phrase searches cannot be done with proximity operators (if anything, the allowance with other searches could only be assumed to extend to these as well). Perhaps this documentation should be temporarily updated to state this is a problem in the interim since this limitation is atypical compared to standard expectations. After all, a phrase search is one of the most common practices in research and content lookups.