If I "fix" or "deactivate" the accounts associated with one ID, the accounts associated with the other ID faile with CC-800 and vice-versa. If I deactivate both and start over, the same behavior occurs.
The was a problem in Dec 2023, "Chase CC-800 errors, two different Chase user IDs" that is identical to the problem I am encountering. Several users reported that issue but the resolution wasn't reported.