Originally Posted by fenrian1

If you look at your code, the Y axis size is 640, the bottom anchor offset for the buf window is 23, placing the bottom of the bufwindow and Y617. The lowest button is at Y542. The buf window is overlaping the buttons.

Your screen shot does not look like it should based on the code you uploaded.
I would try either not using anchors and size the pet window and place it like any other nested window, or maybe try using BottomAnchorToTop>true</
instead of false. Maybe experiment moving the bottom anchor to 150 to give enough room for the button and verify its working.

One other thought, notice the template is WTD_Buffs2. This window uses a custom window template that may need to be moddified and possibly has .tga files that will need to be modded as well.