sometimes randomly when I turn on the Mac the load bar takes longer than normal and when it ends the keyboard doesn't work and I have to force the shutdown. Is this happening to someone else?
Yes, randomly on this machine "white macbook mid 2010", I noticed this even before Mojave announcement, so I'd exclude side-effects of patching, while instead I guess, at least on my machine, trackpad/keyboard are becoming faulty, probably a drop of water inside, however when it happens just power-off the macbook keeping pressed power button for 5 seconds, then power-on and they will work normally again.