Solution achieved! The problem was that my archive configuration was set on 'daily' when it should have been 'monthly' - as ridiculously simple as that! Now my blogs show as I want them to, which should also make it easier for my followers to refer back to previous film reviews - and I'm happy as Larry. Grateful thanks to Sadie, Bob, Mitch and Jon especially for offering their thoughts and suggestions. Having put the problem out there it gave me the extra incentive to find the answer.
Thanks again for everyone's time.
5 hours ago