Changes to properties of a layer's attributes form not saved when skipping between attributes

[styrke10]

What is the bug or the crash?

If a change one or more Attribute Form properties of attribute A (could be for instance widget type and/or default value), and then skip to attribute B WITHOUT hitting the Apply button, then my changes to the attribute A are not saved!

This is a changed (and unfortunate) behaviour in v. 3.40.x. In previous versions this wasn't an issue.

Steps to reproduce the issue

1. Open a layer's Properties dialog
2. Go to the Attribute Form
3. Pick a certain attribute and change its default value
4. Pick another attribute (without hitting the Apply button)
5. Now go back to the first attribute.
6. Your changes to the first attribute are now lost

Versions

I have noticed this in 3.40.0 and following versions - and I am pretty sure this wasn't an issue in versions prior to 3.40.0.

Supported QGIS version

• I'm running a supported QGIS version according to the roadmap.

New profile

• I tried with a new QGIS profile

Additional context

No response

[nicogodet]

Should be fixed by #60192