Embedded Trello boards (via Smart Links) are sometimes read only, despite user permissions

Issue Summary

Some users are reporting that the Trello boards they embed in Confluence via smart links are not editable, even though they are logged into both products and have permission to edit the board.

Steps to Reproduce

1. Embed a Trello board that you have permission to edit on a Confluence page using a Smart Link.
2. Try to move or edit an existing card.

Expected Results

The card can be moved and edited.

Actual Results

Results vary. In some cases, this works as expected. Sometimes, some functionality works and some does not—such as being able to move cards but not edit them. In other cases, the board is fully view-only.

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available