I am any MYOB Business user and have also had the same problem with old transactions suddenly appearing from 3-4 years ago as 'unmatched' and can no longer reconcile my bank account.
I never turned on Smart Reconciliation, MYOB did it automatically.
All MYOB instructions are incorrect, there is nowhere to switch back to 'Classic View'.
I DO NOT WANT SMART RECONCILIATION, NEVER ASKED FOR IT, CAUSES MORE PROBLEMS THAN IT SOLVES.
I have already wasted hours of time trying to fix something that was working a few weeks ago and now does not work.
MYOB need to fix this and not charge users for their MYOB subscription fees until it is fixed as some kind of compensation for lost time and wages.
TEST YOUR PRODUCTS BEFORE YOU LAUNCH THEM!!
Doing a bank reconciliation is a fundamental part of bookkeeping, how could MYOB not realise 'Smart Reconciliation' was going to stop users from performing an ordinary bank reconciliation. MYOB should have realised this was a problem before causing so much extra work for so many people.