Here is a demo project which demonstrates multiple issues. It uses Mac/Cocoa fpcupdeluxe "trunk" and there is no real code in this project.
....
1) Demonstrates toolbuttons becoming invisible until clicked (just click on the top toolbar to expose them)
2) Demonstrates TPageControl tabsheets misdrawn until clicked
3) Demonstrates TEdit looking very weird with black background until clicked
4) Demonstrates some captions/labels etc. are drawn upside down some places
...
To see all issues simply
- run project
- doubleclick window title bar (minimizes to dock)
- open from mac dock.
There are more ways to trigger above errors, but the above is the easiest to make all the problems visible in one go

I may try to simplify the case further - but for now I would appreciate it anyone can duplicate the problems using my test case.