Mojave works great on my Macbook 5,1 late 2008 Aluminum, with one exception. Force Sleep (Apple-Menu or Alt-Cmd-Eject) needs multiple attempts, usually two or three until the Macbook sleeps. Scheduled sleep (i.e. after 15 minutes etc) seems to work fine. Lid is closed and an external monitor is attached, but this does not make a difference. With ext. monitor removed and lid open, sleep does not work as well. Any idea ?