Turbotax applied entire QBI deduction for LLC to me. What did I enter incorrectly?

We received a K-1 for my husband's LLC, in which he is one of several members.  I filled in all the boxes as asked for by TT from the K-1, and filed the return.  When I looked more carefully at the printed return, I saw that it appears the entire income from the LLC is being used to calculate our qualified business income deduction- not just my husband's portion of the income. (but his income from the LLC is being properly reported)  So,

1. What could I have answered incorrectly in the questions?  I don't think TT ever asked what % ownership my husband has.   I don't even know how I would amend this, since I just answered the questions asked.  

2. How long do I have to wait to amend the return?  Do I have to wait until I get my (too big) refund, (ie until I know the first return has been processed?), or can I do it immediately?  

Thanks!