>>>>> First thing you need to know: the XPression looks the wrong way!
From the lowest layer and then upwards! This explained 99% of my authoring problems.
No need to mess with Z values if you use flat objects only, if you understand it looks from below to the upper line in the object manager!
Another thing you should do, is deselect "text always on top" for each text object. This prevents text from acting normally, to the upside down stacking order of the XPression.
Next problem to tackle is the MASKS and LAYER OBJECTS. A mask should sit below the objects you want to reveal or hide. So create a mask and reveal a text or something. Problem you will get, is that EVERYTHING above the mask in the object manager will be masked as well. Solution: Put the text (or whatever) and the mask inside a layer object. Now put EVERYTHING else in their own layer object as well, because layer objects have their OWN order in which they are visible.
You can correct the layer order when you click a layer object and look for the tab layer order at the right, AGAIN realize the XPression looks the wrong way, so put the background things in a backgroung layer object and make it the first line in the Object Manager AND in the layer order tab!!!! Then go for the second line etc.
If you understand the upside down layer order of the object manager AND use the layer objects (with masks in them) in the same order (on the object manager AND the object layer tab) you will NEVER again get unexpected results!!!
#XPression