Google has a confirmed bug with using negative search operators, a way to exclude words from your search results, within Google Shopping. Danny Sullivan, the Google Search Liaison, confirmed the issue on X saying, "We did have a bug where it wasn't working within some shopping results. That might not be resolved yet."
The example given was a search for [nitto jaguar black -tire] the shopper is trying to exclude tires from the product results but it returns nothing but tires. Here is a screenshot:
Google is aware of the issue and it sounds like it should be fixed soon.
But if you are looking to use the feature to exclude words from your search query in Google Shopping, you are currently out of luck.
Here are those posts:
No, it has not. We did have a bug where it wasn't working within some shopping results. That might not be resolved yet. Have an example you're comfortable sharing?
— Google SearchLiaison (@searchliaison) February 21, 2024
Thanks, yeah -- we want it to be working there again because of exactly this situation, when you need to say "no, but not that thing." Hopefully won't be too much longer.
— Google SearchLiaison (@searchliaison) February 21, 2024
Forum discussion at X.