Still playing with permissions a bit. There I noticed, that the “Page” permission does somehow overrule the “Page&Children” deny permission.
If I understood it right, an explicit deny will deny in any case. It appears that this does not apply if you set Allow on the “Page” permission and deny on the “Page&Children” permission for the same group. The other way around (deny on “Page” and allow on “Page&Children” works as expected).
Did I miss something or is this a bug?
Version 11.3 …
BTW: a feature to display the current permissions applied to the current page would be very handy (but probably difficult to implement)