I select the content type, filter, select and delete the page using the dropdown menu, then the filter resets and I again have to select the content type in the filter because I am not finished.
The filter should remember the settings until it is reset.
I ran into this problem again, now I understand, I can simply edit View and changing the filter option „Remember the Last Selection“. Unlike Drupal, Backdrop use Views for the Content page, I forgot about it when I created this topic.