bending b string problem in guitar

i got my guitar professionally set up by a luthier last year. my b string is in tune and intonated. it sounds fine when i slide. but when i try to bend a whole step, it's mostly flat. i tried to bend any other strings but it's fine and on point. but my b string wont coordinate?

i also tried bending the b string on other guitars and it also seems fine and on point. it sounds like only my guitar has that problem.

any tips on how to fix the issue? thank you.