That probably is the result of the mess MSFT created with trying to fool people that 1909/18363 is a real new build.
That's what you get with Registry-only build changes. To my knowledge, the desktop tattoo string in the bottom right corner uses another source of information to determine the build string. For example, nearly all files are shared between 19H1 and 19H2, so they are still branded as 18362.
Same thing seen if you look at the version field in WSUS console. 18363.xxx shows as 18362.xxx. It also very frequently doesn't match the actual revision (the xxx part on the right of the decimal).