Spfx form customizer edit form gives error

[RaistlinMY]

Target SharePoint environment

SharePoint Online

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

💥 SharePoint Framework

Developer environment

macOS

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

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

Additional environment details

• browser version
• SPFx version 1.19.0
• Node.js version 18.20.2 / 20.15.1
• etc

Describe the bug / error

When you try to open edit form it constantly gives error every second.

New item form works without any problem but the edit form gives error. It doesn't matter it is in gulp serve or published to the server. I tried in both v18 and v20 in node with spfx 1.19.0

Steps to reproduce

1. create spfx form customizer (react) with yo
2. create test list in SP online and add one test item so that there is a item with ID 1
3. modify the serve config for the test list
4. run gulp serve --config=helloWorld_EditForm

Expected behavior

I expected to see the empty custom page when the page starts.

[Perneel]

I'm experiencing the same issue with spfx version 1.18.2 (node 16.13.2, win11, edge). Both with existing and new form customizers. As soon as I run gulp serve I'm getting an error. In the developer tools I'm receiving the same error every second, as mentioned in the post above. This occurs in new, edit and display forms.

So basicly debugging for form customizers does not seem to work at the moment.

[RaistlinMY]

Could this be related to some SharePoint Online update? Because older spfx version doesn't work too and also form customizers still doesn't work in either in workbench or as a published app in production.