You should not change your W2 because the IRS needs to match it up with your original.

TurboTax is aware of the e-filing issue that you are having and is currently working on a solution. An update to fix the issue is expected to be released around 4/5/2019.  

Be sure to sign up for updates to be alerted as soon as there is a solution.  If you do not want to wait for an update, you have the option to paper file your tax returns as this is only an e-filing issue.

You can check out this TurboTax FAQ for more information: Excess 401(k) Contribution Preventing E-filing.

I have been using turbotax for years. I hope it will be fixed soon. I would hate to switch to a different software. I am even willing to file for an extension if there is reasonable assurance that it will be fixed.

To add to my previous comment, this is a bug in 2018 turbotax. I was in similar situation in 2017 but didn't have this issue. 403b excess contribution and 1099-R to correct it worked fine.