I don't know much about your current situation, but if you've got a short stint at a company it's not going to matter too much. "I joined expecting X but when I

I don't know much about your current situation, but if you've got a short stint at a company it's not going to matter too much. "I joined expecting X but when I got there it was Y. I gave it a chance for Z months but it didn't work out" is one of the best answers to "why are you looking for a new role?" If you've got 3-4 of these in the other hand, that's when you might just need to bring and bear it