You need to discuss this with your membership clerk. First off, you need to confirm your MRN is really yours. I've heard of cases where someone gets confused and mixes them up - such as when a Bishop is filling out temple recommends and switches the MRNs between husband and wife.
If your membership record has the wrong birth date, the clerk can fix that. He should also check to make sure there isn't a duplicate record for you. That would explain two MRNs.
Bottom line, you need to start with the clerk and establish which MRN is yours and get your birth date corrected.
Have you searched the
Help Center? Try doing a Google search and adding "site:churchofjesuschrist.org/help" to the search criteria.
So we can better help you, please edit your
Profile to include your general location.