Paid Mail Lite: "Action Restricted" when adding an external forward or enabling IMAP — no restrictions configured

Paid Mail Lite: "Action Restricted" when adding an external forward or enabling IMAP — no restrictions configured

Organization on a paid Mail Lite plan (EU DC), domain verified, SPF, DKIM and
DMARC all configured and passing. Single user, 1/1 licenses used.

Two actions fail with "Action Restricted. Please contact your administrator.":

  1. Mailbox Settings -> Forwards -> adding an external forwarding address
  2. Enabling IMAP Access

I am the organization administrator, so there is nobody else to contact. I have
checked and ruled out:

  - Mail Settings -> Access Restrictions: Total restrictions: 0
  - Mail Settings -> Account Restrictions: Total restrictions: 0
  - Subscription: MAIL LITE - 10GB PLAN, ACTIVE, expires 11/08/2027

Inbound delivery works correctly - test messages arrive in the Zoho mailbox.
Outbound via smtppro.zoho.eu:465 works correctly. Only forwarding and IMAP are
blocked.

If this is the new-account anti-abuse hold, please say so explicitly in the
error message and document the criteria for lifting it - "contact your
administrator" is misleading when the account holder IS the administrator, and
there is no screen anywhere in the admin console that reveals this restriction.

Could a moderator lift the restriction for this organization, or point me at the
setting I have missed? Ticket already open by email, no response yet.