[SharePoint Copilot Apps preview] " IFrame/container height remains same in expand and collapse mode

Target SharePoint environment

SharePoint Online

What SharePoint development model, framework, SDK or API is this about?

💥 SharePoint Framework

Developer environment

Windows

What browser(s) / client(s) have you tested

• 💥 Internet Explorer
• 💥 Microsoft Edge
• 💥 Google Chrome
• 💥 FireFox
• 💥 Safari
• mobile (iOS/iPadOS)
• mobile (Android)
• not applicable
• other (enter in the "Additional environment details" area below)

Additional environment details

SPFx version. 1.24.0-beta.2
Node.js version : v22.21.1

Describe the bug / error

When an SPFx Copilot Component is rendered inside Microsoft 365 Copilot, the component iframe appears to use the same height in both collapsed and expanded states.

Expanding the component does not trigger a resize of the iframe/container height. As a result, the expanded view is constrained to the same height as the collapsed view.

From browser inspection, the iframe is rendered with a fixed height value:

Steps to reproduce

1. Create and deploy an SPFx Copilot Component.
2. Open Microsoft 365 Copilot.
3. Trigger a response that renders the component.
4. Observe the component in collapsed state.
5. Expand the component.
6. Inspect the generated iframe/container element.

Expected behavior

The iframe/container height should be recalculated when the component is expanded so that the expanded content can be fully displayed.