Box 2a is permitted to be less then box 1 in most cases and often is.
By any chance is the IRA/SEP/SIMPLE box checked on your 1099-R or did you accidentally check it?
If so, uncheck that box or delete and re-enter the 1099-R. That box is only checked for a Traditional IRA and a PERS account is not an IRA.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**