P.P.S.:
I’ve grapped yor suggestion and tried it again…
1. If I edit another “old” page, the changed value of a “new” field ist stored – that was my anticipation is for every page-post, actually.
2. The problematic page is the Start-page. Even this was not set in the Theme, I set it and enhenced the rule with “OR [page type is equal startpage]” – the “new” field isn’t stored.
3. I enhanced the rule furthermore with “OR [page is equal <page-title>]” – no effect, the “new” field for the post-id of <page-title> won’t be stored.
…
