Do you want an offer? Don't be yourself: be who they need. If it requires you to be a bit different from who you are, so be it.
Once you get the offer, the power structure changes: you're the one in control. You're the one now faced with the tyranny of choice. This is when you can decide whether accepting this job would be at odds with who you are. But you know what? Even if that's the impression you got from the interview, your job at that company might still end up being different. You could end up in a team that's completely different from the ones who interviewed you. Or the job might end up being different. Or you might end up finding out you like things you didn't think you would.
Get an offer. At all costs. Then you're in charge.