No idea how to update to 10.15.4. Am I doing something wrong?

When I click "Update now" and then "restart", I get logged off, and then go to the apple logo with the loader bar. I starts at 5% and doesn't go anywhere, and then the computer just...restarts? And I get loaded back into the login screen and my computer is still on 10.15.3.

I already updated clover (to 5109) and all my kexts, and I re-enabled SIP. Any help is appreciated.

If I select "Boot install from mackintosh HD" in the boot menu, I get this screen but it hangs there and then restarts again.

Author: @The_Chillosopher