If each and every one of your individual transactions don't appear individually on the Form 8949 you e-filed with your return, you'll need to send supporting statements that reflect the individual transactions to the IRS with Form 8453.
The IRS needs to see each transaction separately so that it can match up information it’s received from each of the reporting institutions.
According to E-file in the Instructions for Form 8949, you can either attach Form(s) 8949 showing all the individual transactions to Form 8453, or
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.
If each transaction is reported separately on Form 8949, it’s not necessary to send in Forms 8453 and 8949.
There are no known program issues related to what you’re describing.
