Version used
3.19.2
Describe the bug
Standard search Boolean Operators do not seem working. When I did "Automotive NOT BMW" in search box, the results were documents contains "Automotive", "not" and "BMW". Similarly "AND NOT" does not seem working neither.
To Reproduce
Expected behavior
The results documents contains word "Automotive" but not "BMW".
Screenshots

Desktop (please complete the following information):
Additional context
Cannot repro. You should test the same query in OOB search. If you see the same issue, then report an issue with your tenant as it's not web part related, but API related.
I tested OOB search results page and it worked as standard Boolean operator. Just this PnP Modern Webpart does not work....
Should i use different version?
Ack as a bug.
Forgot to mention...
"Automotive -BMW" (minus '-' as 'NOT') worked. It resulted only documents with "Automotive" not contains "BMW"
Hope this helps!
I'll get a fix in for the next release.
Will be part of v3.21.0