If you set Choice as Required component, it functions if “Write to” refers to the table selected for the tab in concern. If “write to” is set e.g. for User profile row, “Required” doesn’t work.
Evidence:
Screenshot above shows CORRECT functioning of Choice when required and nothing selected, if Write to field (“IndEdit”) is in the table joined to this screen (Submit is blocked because nothing was selected).
In the case when we have Write to the field “AktEdit” in User profile row, we have the bug:
… for the very same component Submit is not blocked. Bug: “Required” clause doesn’t function in that situation!