SPFx Field Customizer - some Field Properties don't seem to be working properly

[sys-tim-buecker]

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

• browser version: Version 147.0.3912.72 (Offizielles Build) (64-Bit)
• SPFx version: 1.22.2 - Heft
• Node.js version: 22.22.0

Describe the bug / error

When updating a Field Customizer field definition in elements.xml and setting:

ReadOnlyEnforced="TRUE"
ShowInDisplayForm="FALSE"
ShowInEditForm="FALSE"
ShowInNewForm="FALSE"

those settings are not applied after deployment. The field renders normally in the list, but it is still editable and still shown in views/forms, even though it should be read-only and hidden.

Steps to reproduce

1. Create a new SPFx project
2. Updating field definition in elements.xml and set the props
3. Upload to App Catalog and deploy
4. Add field to List View
5. Test the field

Expected behavior

• Field is enforced read-only (ReadOnlyEnforced="TRUE") (User can not update the field)
• Field is not displayed in: Display form, Edit form, New form

[Ashlesha-MSFT]

Hello @sys-tim-buecker
Thank you for bringing this issue to our attention. We will look into it and get back to you shortly.
If you don’t receive a reply within two working days, please use this escalation form to escalate.

[Ashlesha-MSFT]

@sys-tim-buecker,
Thank you for the detailed report. I was able to successfully reproduce this issue on our end using SPFx 1.22.2 with the same field configuration.
I have raised this with the engineering team as a confirmed bug. We will investigate the root cause and keep this issue updated once a fix is available.