App page property pane follows navigation into unrelated webparts

[Drenam1]

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

Chrome Version 135.0.7049.115 (Official Build) (64-bit)
SPFx version 1.18.0
Node.js version 18.20.4

Describe the bug / error

If you open the property panel on an App page with an SPFx webpart, then close it (or leave it open) and navigate to another page with webparts (custom or out-of-the-box), the App page title and header will appear in the property panel for any webparts edited.

Steps to reproduce

1. Navigate to an App page with a full-page app.
2. Edit the App page to see the property panel. Close it without changes, leave it open, etc - it makes no difference.
3. Without refreshing, navigate to another page with webparts.
4. Edit the page and open the property panels for some webparts. You will see the App page title and the header at the top of the property panel. This happens for both custom and MSFT webparts.
5. If you refresh the page, this behaviour disappears.

Recording.2025-05-12.153832.mp4

Expected behavior

When you open the property panel for a webpart, you should only see properties for that webpart not for previously opened webparts.

[Ashlesha-MSFT]

Hello William Brook (@Drenam1),
Thank you for bringing this issue to our attention. We will look into it and get back to you shortly.

[Ashlesha-MSFT]

William Brook (@Drenam1),
I’m trying to reproduce the issue, but I’m not seeing any web parts when editing the page where I added the app.
Could you please clarify the steps a bit more?
Also, if possible, could you please share the SPFx solution or an example App page setup so I can test it accurately?

[Drenam1]

The initial app (in steps 1-2 of my instructions) needs to be a full-page SPFx webpart, configured with SharePointFullPage as its supported host like in this article. The webpart then gets added to the page via New > Page > Apps

There are no out-of-the-box webparts like this as far as I know - however, any of the SharePointFullPage SPFx sample webparts should work for reproduction purposes.

[Ashlesha-MSFT]

William Brook (@Drenam1),
Doing the same, to test.

I was able to reproduce the issue only once, and that was the first time I published the page.
After several refreshes, I could no longer reproduce it.

[Drenam1]

William Brook (@Drenam1),
Doing the same, to test.

I was able to reproduce the issue only once, and that was the first time I published the page.
After several refreshes, I could no longer reproduce it.

Strange... it happens for me every time I go from editing an app page and saving, then navigating to a normal page

[Ashlesha-MSFT]

Just following up to see if you're still experiencing the issue with the App page property pane showing up on unrelated web parts.

[Drenam1]

Ashlesha-MSFT Yes this is still happening

[Ashlesha-MSFT]

William Brook (@Drenam1),
Thank you for your continued support and follow-up on this.

After further investigation and repeated testing (about 5–6 times), I was able to consistently reproduce the issue as originally described. It seems to occur reliably under the stated conditions when navigating from an App page with a full-page SPFx webpart to a regular page with other webparts, without refreshing the browser.

We will go ahead and create an internal bug for this so that the engineering team can take a closer look.

Apologies for the earlier misinterpretation and the delay in response. Appreciate your patience and help in tracking this down.