Primary admin actions block on view dissapears if change path
The LocalActionsBlock is a block plugin that displays menu action links for a given route based on the LocalActionManager::getActionsFromRoute method.

The route that corresponds to the path /admin/content has action links, but whichever route that corresponds to the path you are using does not have any action links defined.

Action links are defined in MODULENAME.links.action.yml file.

If the desired outcome is to have the local actions that correspond to /admin/content on a different path, then a module should be created that defines additional action links for those routes.