After e-filing was sumbitted, TT is telling me to mail Form 8453 for Form 8949?

[Denisen]

I am apologize in advance for the combination of questions and complaining that this will be...

For the first time in many years of e-filing with Turbotax, it is telling me I need to manually mail a form to complete the filing.  Form 8453 generated and has a 'X' next to Form 8949, yet it didn't include an 8949 form as part of the document it generated for me to mail in.  How about including the related one for simplicity?

When I look at the 8949 line on the 8453 form, it indicates "if you elect not to report your transactions electronically".  I was never prompted to elect or not elect to do so.  That would have been a nice pop up in the many checks that TT does.  Something like "We can't report X transaction electronically because of Y issue, do you want to fix it or proceed as-is?"

Moving on...

I checked my normal tax documents TT generated on the next screen and see four 8949s.   Am I supposed to print a specific one or all of them?  If a specific one, how do I know which one?

Looking at other online questions about this scenario, I found comments about this happening to others because a summary was entered instead of individual transaction details, plus something about needing to also send the 1099-b that it is for. 

Of my four 8949s, I do see one is related to some cryptocurrency that I didn't get a 1099-b for and ended up having to enter as a summary (since Turbotax desktop version doesn't support CSV import). So is that the only one 8949 I should be including in what I mail? 

Also, do I send just 8949 (which was part of the filing) or do I also need to send the gain/loss report that it relates to.  If both, why doesn't the TT instructions say that?  Something like "Send the 8453, 8949, & supporting 1099b or similar document"? 

[ErnieS0]

You only have send documentation to the IRS for transactions where the cost basis was not reported to the IRS by your financial institution.

It appears you will only have to send information about your cryptocurrency.

The IRS says:

If you e-file your return but choose not to report each transaction on separate row on the electronic return, you must either (a) include Form 8949 as a PDF attachment to your return, or (b) attach Form 8949 to Form 8453 (or the appropriate form in the Form 8453 series) and mail the forms to the IRS.

You can attach one or more statements containing all the same information as Form 8949, instead of attaching Form 8949, if the statements are in a format similar to Form 8949.

2021 Instructions for Form 8949