I've checked my password, I signed up for multi-key authentication and tried it. When that failed, I removed it so I am back to normal but nothing is working. Would appreciate any help so I dont have to manually enter all of the transactions.
I was able to fix this issue by logging into Betterment and going to Settings > Security and creating an "app password" for TurboTax. I was able to provide my username and the app password in place of my password in TurboTax and it then worked.
It seems to be a known issue among TurboTax customers, but the issue isn't acknowledged by TurboTax staff. I haven't seen any sort of response from Intuit on this.
Here is a thread with a bunch of responses: https://ttlc.intuit.com/questions/3651286
I don't know if there is anything you can do. Intuit needs to act on this problem.
You have to go into your Betterment settings, then Security, and create an app password