Here are two recently posted answers to this question:
Other users have reported not being able to import from Acorns as well.
I've reported the importing issue to a TurboTax Moderator, who should see it today. Hopefully, they can troubleshoot it soon or have more info.
mesquitebean
That is a question to ask Acorns. TurboTax only supplies the import server that is common to all financial institutions. The financial institution must supply the data file that is coded in the standard import format.
macuser22
See: Is anyone having problems importing Acorns Tax Documents?
I ran into the same issue.
Two things I think helped me overcome this issue...
1. The Account ID I fetched from the 1099-B statement had 000 prefixed to the account id. I used the exact account ID (with 000 prefixed), and that worked fine.
Earlier I was using the account id which shows up on their website (without 000), and I think that was preventing the import.
2. The document ID I fetched as-is from the 1099-B pdf statement...(with spaces in it)
Thanks