In the month of March Apple presented in society the Mac Studio that was accompanied by the Apple Studio Display. A screen specially made for this Mac. Less expensive than the Display Pro but not so cheap that the company makes this mistake about its update. It seems that some users have experienced problems when updating to the latest firmware and the problem is not that the software does not work correctly, it is that the company seems to have forgotten the screen itself. But it's all fixed now.
Some users have registered their complaints on the Apple discussion forums about not being able to update the display to the latest version 15.4 firmware. Instead, a message appears: “The Apple Studio Display firmware update could not be completed. Please try again in an hour. If the problem persists, contact an Apple Authorized Service Provider." At least one user also said that the failed update prevented their Mac from updating to macOS 12.3.1 until they unplugged the display from the computer. There were also cases where the Studio Display tried to update, but the progress was interrupted and would not start again. It stayed on a notice: "Preparing." But it seems there was nothing to prepare.
According to an Apple support document on firmware update, version 15.4 includes support for Boot Camp on Macs with an Intel processor and minor stability improvements.
But there is not much to worry about. Above all, users must remain calm, because the problem is not the screen, far from it. The problem is that Apple, on Friday, stopped signing iOS 15.4 after releasing iOS 15.4.1 on March 30. When Apple stops signing a version of an operating system, it's no longer available and devices can't install it. Since Studio Display is essentially based on an iPhone 11, version 15.4 could not be installed correctly, and 15.4.1 is not available for Studio Display.
Last night, Apple had fixed the issue by allowing 15.4 to be re-signed. To update the firmware on the Studio screen, your Mac must be running macOS 12.3.1, and if the update is available, it will appear when you run Software Update in System Preferences.