I see conflicting responses in reporting excess elective deferrals in 2018.
Do I need to report it as a 1099R even when we don't receive one (or)
do I need to report as an excess deferral in Miscellaneous Income, 1099-A, 1099-C?
In either case, Turbotax isn't allowing to eFile and spinning in a loop.
Both of the options you list above result in the correct outcome. Either option adds the excess contribution to your wages on Line 1 of your Form 1040.
As far as the e-file loop you are stuck in, it was just announced that an update is currently planned for April 12th, 2019 to resolve this e-filing issue.
You may still see a warning about the excess contribution, but you should be able to e-file. You can check out this TurboTax FAQ for more information: Excess 401(k) Contribution Preventing E-filing.
April 12... There are still 3 more days, what's the rush...
If you cannot have it removed by April 15, then it can stay in the plan but must still be reported as taxable wages using the method below since you will not receive a 1099-R. Since it was not removed before April 15 when you finally distribute it at retirement, it will be taxed again - that is the penalty for not timely removing it.
This is explained in the IRS pub (link below).
Excess 401(k) deferrals should be reported in:
(There are several screens to click through to get to the right place)
Miscellionious Income ->
Other Income not reported on a W-2 ->
Other wages (yes) ->
House Hold employee (Continue) ->
Sick Pay (Continue) ->
Other earned income (yes) (Includes excess salary deferrals)->
Source of income (other) ->
Any other income - enter the amount of the excess deferral and an explanation.
This will add the returned excess to your 2018 wages on line 1
For information see IRS Pub 525 page 10
https://www.irs.gov/pub/irs-pdf/p525.pdf