If the above suggestions are not working it may be because the bookmarks can contain zoom instructions in their properties. To look at the bookmark properties select a bookmark in the bookmark panel and right click it to open properties. Choose actions. There should be a description of actions that will be applied when clicking on the bookmark.
The best solution I have found is that you can add a subsequent property for zoom instructions that will execute following the initial one, and set the page zoom to your specifications. To do this, select all of the bookmarks, right click to open properties, then actions, then choose the add function. After choosing add, find the zoom instruction that is the best fit for what you are looking for.
If you want to edit the initial zoom instruction through the edit function in bookmark properties on all bookmarks, you cannot select all, because, although the zoom will be set correctly, every bookmark will be set to one bookmark page. If you wish to edit the properties this way you must edit each, one by one.