Upgrading Minecraft Server from 1.20.1 to 1.20.5 (Unintended JRE downgrade ?)

Reporting here bcs a category for Java Edition Servers is missing (matching overall customer experience SMH)

Runs fine with server.jar (1.20.1)

and crashes with the below error once i switch out the server.jar (1.20.5)

BTW great tutorial [NOT] on official site https://www.minecraft.net/de-de/download/server says minecraft_server.1.20.5.jar but spits out a server.jar [clapps]

Fehler: Beim Laden der Klasse net.minecraft.bundler.Main ist ein LinkageError aufgetreten
        java.lang.UnsupportedClassVersionError: net/minecraft/bundler/Main has been compiled by a more recent version of the Java Runtime (class file version 65.0), this version of the Java Runtime only recognizes class file versions up to 64.0