Post AP batches to period 1 2021

I am posting my first AP batch for 2021 and received an error stating that the period is currently locked and posting is not allowed.  We did not lock the period but I do see in Accounts Payable - Process Period End that there is an option for me to Unlock AP Period 1-2021 however when I select the option to do so, I receive a message telling me that unposted transactions exist.  Do you still want to close the period?  Obviously I do not want to close the period, I simply want to unlock the period.  What do I do here?