I finally had success importing my Merrill Edge information today. It required a few things.
1. Merrill had delay in posting documents. If you tried before that was ready (3/20?), results would not be good.
2. TurboTax and Merrill would not interact from my MacBook when using wi-fi. I got “Unsuccessful” check your internet connection messages.
3. Although I could login to Merrill in a browser on the machine, the TurboTax connection would not make that hop (wired or wi-fi) until I did a password reset on my Merrill account.
4. That Merrill reset raised some issues, likely by the unusual login attempts, and locked my account shortly after a good browser login with the new creds. That required a second password reset.
Once the ML account had the new password and was no longer locked, TT failed to import over wi-fi. TT immediately got the data when I used the wired connection.
Note: My other imports from similar institutions worked over wi-fi. Only the Merrill connection gave me grief.