When a connection row exists for the user but with a different/null evotor_user_id, the lookup by evotor_user_id alone missed it and tried to INSERT, hitting the unique constraint on user_id. Now looks up by either evotor_user_id or user_id, and always syncs both fields on update. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>