[MM3-users] Held messages page not rendering the message

Hi

When the list moderator goes to the held_messages page, they correctly get a list of the held messages and can accept/reject/discard them

However, clicking on the individual message to read it doesn't work - it does nothing visible at all. From debug I can see it requests /mailman3/postorius/api/list/<list>/held_message/1/ which returns correctly (and the body includes the message as expected) - but it never renders it

Any idea what could be wrong?

Thanks

-- Mike