When I try a simple KQL search for the character pattern:
it finds no results even though I can see that string pattern in some entries of an unfiltered query of my data stream. According to the KQL documentation, the characters above do not require escaping. Nevertheless, I tried escaping each of the two unique characters, in turn, then tried escaping all of them. I still got no results back from each of these queries.
Is there some restriction on which characters can be used in a query?