Menu Block not shown if parent item is view

The first step is to determine which change in 9.5.9 → caused the regression.

@cilefen: Yes, I tried, but how can I achieve that? I did not find one of the issue descriptions obviously near to the problem. There are many entries in the list I don't complete understand what they do. Perhaps anyone else with more knowledge about drupal core can help to find the issue caused this problem.

I did not find one of the issue descriptions obviously near to the problem.

I did not either. If you have the time and the means, you could perform a git bisect between 9.5.8 and 9.5.9 on a Git checkout of Drupal Core. That will certainly find the commit that changed the behavior.

I think this is a duplicate of 🐛 [regression] missing menu active trail in Drupal 9.5.9 Needs work