For Merrill, I saw another user changed their password for Merrill and then was able to import.
User solution:
The ultimate solution, although I do not understand why, was to change my Merrill password. Once I did this, the import worked fine. My previous password worked in Merrill, but for some unknown reason when I used the same ID/Password in TurboTax, I could not log in.. Simply changing my password in my Merrill account and then attempting the import with the new password worked.
If you are using TurboTax Online, try importing using a different browser. Make sure any VPN or Anvi-Virus is turned off.
See the following TurboTax Help articles for potential fixes:
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"