This is not a Make bug.
Google Drive does not have a “negative” search operator — you cannot use - to exclude words.
For more information, check it out yourself by clicking the advanced search icon to build your own query:
Hope this helps! Let me know if there are any further questions or issues.
— @samliew
P.S.: Did you know, the concepts of about 70% of questions asked on this forum are already covered in the Make Academy. Investing some effort into it will save you lots of time and frustration using Make later!