macOS Catalina 10.15.4 won't be installed on my Mac.
I think it took several hours to down load it but it takes several seconds to install it on my Mac.
Whenever Apple logo and progress bar are shown, it just take several seconds for the progress bar to complete. After finishing progress bar, my Mac reboots and shows windows which tell me there are an available update macOS Catalina 10.15.4.
I have no idea why it won't be installed on my Mac.
MacBook Pro 15", macOS 10.15