By default on macOS your floating Palettes become invisible when you switch to another application. This has both its advantages and disadvantages, but if you really need to see the content of some palettes of ARCHICAD, while cross-referencing it with some other application (PDFs, sheets, Help Center, etc.), you have the option to do that.
All you have to do is to simply go to ‘Work Environment/Dialog Boxes and Palettes’, and turn on the ‘Keep ARCHICAD Palettes visible even when another application is in front’ option.
After that, the floating Palettes should stay visible, even when you just check something on Help Center quickly!