ComponentLookupError for JSONField in tests

Tests for a change in plone.app.dexterity are fine (tox).

But CI tests raise a ComponentLookupError for an ordinary plone.schema.JSONField.
Any hint is welcome.

      File "/home/runner/work/plone.app.dexterity/plone.app.dexterity/.tox/test/lib/python3.11/site-packages/plone/z3cform/layout.py", line 45, in update
        self.form_instance.update()
      File "/home/runner/work/plone.app.dexterity/plone.app.dexterity/.tox/test/lib/python3.11/site-packages/plone/z3cform/fieldsets/extensible.py", line 62, in update
        super().update()
      File "/home/runner/work/plone.app.dexterity/plone.app.dexterity/.tox/test/lib/python3.11/site-packages/plone/z3cform/patch.py", line 31, in GroupForm_update
        _original_GroupForm_update(self)
      File "/home/runner/work/plone.app.dexterity/plone.app.dexterity/.tox/test/lib/python3.11/site-packages/z3c/form/group.py", line 132, in update
        self.updateWidgets()
      File "/home/runner/work/plone.app.dexterity/plone.app.dexterity/.tox/test/lib/python3.11/site-packages/z3c/form/form.py", line 136, in updateWidgets
        self.widgets.update()
      File "/home/runner/work/plone.app.dexterity/plone.app.dexterity/.tox/test/lib/python3.11/site-packages/z3c/form/field.py", line 253, in update
        widget = zope.component.getMultiAdapter(
      File "/home/runner/work/plone.app.dexterity/plone.app.dexterity/.tox/test/lib/python3.11/site-packages/zope/component/_api.py", line 104, in getMultiAdapter
        raise ComponentLookupError(objects, interface, name)
    zope.interface.interfaces.ComponentLookupError: ((<plone.schema.jsonfield.JSONField object at 0x7f6dc35c4dd0 plone.dexterity.schema.generated.plone_5_1681896458_2_2634134_0_plonista.plone_schema_jsonfield_jsonfield>, <WSGIRequest, URL=None>), <InterfaceClass z3c.form.interfaces.IFieldWidget>, '')

See Content types control panel: Add schema identifier to behavior description · plone/plone.app.dexterity@e9014ff · GitHub

Does the test-setup load the ZCML of plone.schema?