Support solved it. Here is their reply:
Hi Vlad, thanks for reaching out! We have a flag in our system for increased security, and looks like your account was accidentally flagged. I’ve marked yours as safe so you’re set to share, and the issue should not reoccur. Let us know if it works now.
I also let them know about this topic thread and that others face the issue.
So anyone else getting this error, Coda support is the only one that can help.
Cheers,
V