os 4 needs to run setpatch and start again. so be sure to catch the second boot and disable dh0 again.
an easier method is to give a higher priority to os 4. this way it will directly boot to ps4 without any problems. for os 3.9, you need to enter boot menu and select dh0 for boot device. but remember, if you have romupdate patches in your setpatch, it will restart, so you need to catch it and select dh0 again.
I have a 3.9 rom in my system, so I skip romupdates, which boots to 3.9 without any restart.
