For the past month I've been getting FDP-101 when attempting to sync my SEI account. Last successful sync was 36 days ago. I had MFA properly configured and working for some months. Since you seem to have so much trouble with the SEI connection, I have not tried any troubleshooting on my end other than retrying periodically. I do get the prompt for MFA, I get the MFA code via text message, and I enter it, then wait for a while until I get the error.