Many thanks for your response, super helpful. And indeed, this tokenization is very counter-intuitive, at least for newbies who don’t have a clue how it works under the hood.
Actually, I tried using the regexp version, but I didn’t include the wildcards, because usually /foobar/ is equivalent to /^.*foobar.*$/. I didn’t find any info in the docs about the implicit ^ and $ that seem to be applied, which is why my approach was unsuccessful.