Task Level Dff Page Composer in Project Financial Management

We have a requirement to personalize a Task-level Descriptive Flexfield (DFF) attribute on the Project Financial Management page in Oracle Fusion. Specifically, we need to:

Make one of the Task DFF attributes read-onlyApply an EL expression to control the Rendered property of the attribute

To achieve this, we attempted to use Page Composer within a Sandbox. However, we are encountering an issue where the Task-level DFF components are not visible in the Structure pane of Page Composer.

In this page, the Task DFF appears as a pop-up (modal window). When the modal window is opened, Page Composer becomes inaccessible, which prevents us from selecting or modifying the DFF fields.