MacOS10.13.6 and later versions cannot be automatically upgraded to a later solution

I’m used to automatic updates for macOS, XCode and iOS on the App Store. I recently upgraded my iPhone XR to iOS version 12.2. During real machine debugging, a message is displayed indicating that XCode must be upgraded to version 10.2. I opened the App Store and found the operating system is 10.13.6, which is already the “highest version” and cannot be upgraded. There is an incompatible upgrade below, click to see the XCode upgrade. Finally click upgrade and the following error will be displayed:So why can’t the App Store update macOS to 10.14.3? A lot of websites don’t support phones below iPhone7 after they upload iOS13 recently, so think about the possibility that apple has abandoned us. My computer is only two years old. It’s not even three years old. The products supported by macOS Mojave are:It works with my MacBook Air (13-inch, Early 2015), so why can’t it automatically upgrade? Check it out at the Apple StoreMacOS Mojave upgrade connection.Then click here to view: Mac App Store Jump to the Mac App Store, see macOS Mojave, click to get is a long wait for the download to complete the upgrade. After macOS has upgraded to 10.14.4, search for XCode in the Mac App Store and click to get it. After the upgrade, the Mac App Store was completely different.MacOS 10.13.6 is not supported by the old Mac App Store. It is a problem with the Mac App Store upgrade tool. It seems that automatic is not completely reliable, there is time will also put a mistake, go to the Internet to check, mobile phone upgrade is also need to be!