over contributed to 401K with job change. I followed the instructions to record addl income. Now trying to file my return and I am stuck in a loop after I press "transmit returns now" that goes to "we need to make one more check" that points out that I have over contributed to my 401K on Form 1040 which is not filed.
You have taken the right steps including the excess deferral on your 2018 Tax Return.
At this point, I think you are running into an e-filing issue within TurboTax. An update to fix the issue is expected to be released around 4/5/2019. You can check out this TurboTax FAQ for more information: Excess 401(k) Contribution Preventing E-filing.
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.