I redid my 2017 and can't find the issue the IRS says

What issue is that?

Did you get an IRS letter about your 2017 return?    I assume you got one with the issue.   Is there any clue in the letter as to what "the issue" is?    

What type of IRS letter did you receive?  There should be a CP or LTR number in the right corner.

"I redid my 2017"

How did you do that?    Do you have the 2017 desktop software and used it for experimenting to see if you could reproduce "the issue?"   Online TurboTax is now only for 2018 returns.

If you purchased Audit Defense for 2017, we can tell you how to speak to the company that handles that service (intuit.taxaudit.com).

If you did not purchase Audit Defense, you can phone the TurboTax free Audit Support Center to speak to a live person for help with an IRS letter.   To get the phone number go to the page at the link, click the blue "Get Help" button, and follow the prompts:
https://support.turbotax.intuit.com/irs-notice/audit-support/

In the meantime, you may also get help in this forum, if you explain what the issue is.  Hopefully, someone familiar with it will be able to comment.