How to use the \b to make filter works correctly?

I want to get the sentence with “dog”, exclude “doggie”, “bigdog”, but include “叫dog”, “dog叫”.

I use \bdog\b, it will exclude all the example words above.

I’ve tested it in regex101, it works as I wish, so could anyone help me to solve this? Thanks.

I found \w is not only [A-Za-z0-9_] in ttrss, it also includes all Chinese characters.

Maybe that’s the reason why \b is not the same as the regex101 tools shows.