The problem with Windows 10 Enterprise LTSB 2015 is that it doesn't receive any Windows upgrades nor Windows Updates like Optionals but only Security updates.
The latest AMD Driver depends on you having the latest Windows Updates, both Security and Optionals, and version installed.
I believe that is why it is saying that your Windows 10 version is incompatible since it is still basically a 2015 Windows version which isn't supported by Microsoft anymore and not compatible with the latest AMD Drivers.
So you will probably need to download AMD drivers from 2015 to be compatible.
Found this website that explains about LTSB versions:https://www.computerworld.com/article/3250464/faq-windows-10-ltsb-explained.html
So what is Windows 10 LTSB?
Officially, LTSB is a specialized edition of Windows 10 Enterprise that promises the longest intervals between feature upgrades of any version of the operating system.
Where other Windows 10 servicing models push feature upgrades to customers every six months, LTSB does so only every two or three years. That means fewer changes during a set timeline, a less-involved upgrade effort, and fewer disruptions as well as fewer possibilities for applications breaking because of a modification of the OS.
The even earlier Windows 10 Enterprise 2015 LTSB – based on the July 2015 debut version of the operating system – still receives security updates, of course.
