Why does TurboTax require ex common law info when listing single (post 90 days separated before December 31st) while also giving an error when that info is entered?

[TurboTax-User]

There is conflicting information on the TurboTax Site. 

On my return, I listed "On December 31, 2017, I was single"

TurboTax Help - Marital Status

> Separated - December 31 of the tax year, you had been living apart from your spouse for more than 90 days due to marital breakdown.

TurboTax FAQ (https://turbotax.community.intuit.ca/replies/3465608)

>Single: You were living common-law but you’ve been living apart from your partner for at least 90 consecutive days due to a breakdown in the relationship. There are no tax implications whether you choose “Separated” or “Single” after the breakup of a common-law relationship.

Review: Errors

> Your marital status cannot be single if you've entered information about your spouse/partner. Ensure that you've entered your marital status correctly, noting that if you were divorced, widowed or became separated in 2017, your marital status cannot be single.

Changing my status to "separated" resolves the error, but to according to the TurboTax FAQ I should be able to file as Single. Is it true that once you've been in a common-law relationship, you are never considered single by the CRA, and must file as "separated"?

Edit: After looking into this further, I really believe that requiring this information is a bug in the Turbotax system. The print out version of the tax return has 

Marital status

Tick the box that applies to your marital status on December 31, 2017:

1 Married 2 Living common-law 3 Widowed 4 Divorced 5 X Separated 6 Single

And then,

Information about your spouse or common-law partner (if you ticked box 1 or 2 above) 

If I was filling this out on paper, I wouldn't have to include my ex common law partner's information. Turbotax should fix this. 

[TurbotaxRobert · Accepted solution]

The reason that you are unable to enter your marital status on December 31 as "single" is because you have entered information about your spouse/partner in your return (see Review:Errors that is part of your question).

Also, as stated in part of your question, there are no tax implications whether you choose "Separated" or "Single" after the breakup of a common-law relationship.

As a result of the above, you will have to enter your status for 2017 as "separated" (because you have entered information about your ex in your return) but, for 2018 and future years you will be able to indicate your marital status as 
"single" once again (because your returns will no longer make reference to your ex).  Hope this helps.

[TurboTax-User]

Can you re-review this? Check out my additional details. Turbotax requires you to add your spouse's info, even if you're not checking off box 1, or box 2 on the Marital Status section of the return.

[TurbotaxRobert]

The information that the TurboTax program asks about the previous spouse's (or common-law's) income during the year that a separation takes place is requested because there may still be an available spousal tax credit claim (for the period during the year when they were still together) and this claim will be based on the income of the previous spouse or common-law partner while married.

[TurboTax-User]

That makes sense. Then, in the case that this claim isn’t available, the system should probably not raise an error if the current status is set to Single and should properly submit without any ex-spouse information (as a paper submission would be, for that case).