My unsigned 2017 (a refund) was returned by IRS. I need to correct 2017. I've already started the 2018 return. Will the change be reflected on 2018 by the software?

[Rachel_W]

No, the changes you make in the 2017 software will not be changed in the 2018 software if you have already started your 2018 Tax Return.  You would need to rollover your 2017 Tax Return to 2018 after you made the changes, but that would erase everything you have done so far in 2018.