请教mega backdoor 报税

请教：我用HR Block报税，W2 box 12只有$19500 401k contribution, 但软件显示excess retirement contribution and treat excess contribution as wages. 这个跟我after tax 401 contribution and roll over to mega backdoor Roth IRA有关吗？那张1099-R的表都还没输入，软件就说based on W2 box 12, over contribute了。请问大神如何fix呢？多谢！