I normally default to SearxNG search engine but sometimes use swisscows.com.
For some reason, if I let FOSS browser remove the tracker portion of the search, it will no longer work. If I allow the tracker to be used, it works every time. I have tried multiple Searx engine instances, and they all seem to have the same issue.
You should probably report that to the browser developer. Sounds like their tracker filter has a bug causing false positives.
That’s probably reasonable.