It looks like the area code mismatch is NOT an error which should halt an prevent the user from saving their change. I would propose you change the flow a little (see below)
###Changes:###
- Allow the user save if area code does not match the state.
- Show a notification (not an error) under field(s) in question.
Such approach will not force the user to save twice and will notify them about a potential issue which they can go an fix instantly.
Additional detail:
I am assuming the form also has an area code field, notice should be visible under both allowing the user to adjust the area code or change the state.