That's a good point. For some reason we don't adjust the pronunciation on that one, but we do on other words like "contract": 'contract (noun), con'tract (verb).

The word "research" is an odd one as it's pronounced as re'search as both verb and noun in BrE but 'research as both verb and noun in AmE.

But, of course, many British speakers now use the American way without realising (as evidenced by replies to my original comment).