I have brought this issue to the attention of Matomo and they were able to replicate is, as seen above. In my case the /index of pages we want to exclude are still shown in the pages report. Indeed the /index of this pages are not shown in the visitor logs.

I think that is kind of expected behavior as segments in Matomo work that way. A segment is always used to filter the list of visits that are included in a segment. So when using a segment like page url does not contain Matomo will select all visits that have a page view with a url that does not contain something. It will not exclude a visit if there is an action that contains the defined url (if there are also other actions). Afterwards when generating the reports the excluded url will so be contained in the reports again, as it is part of a visit that is included in the segment.

@sgiehl But in that case would we not expect to see that in the Visits Log when viewing the segment?

Isn't is the same as:
#17388
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@Starker3 you will also see that in the visits log. What you wouldn't see there is a visit that only has an action with the excluded url. But as soon as visit also has other actions it will be shown.

FYI And it likely refs #14664

Thanks for the additional info @sgiehl
When I check the Visits log for All Visits we can indeed see some visits that contain other actions:

However, if I apply the segment from the screenshot above (That excludes any Page URL with /selection), then there are no visits shown that include this Page URL in all ~900 visits in the segment: