When I start the version 1.21.4 from the "Latest Release" profile in Minecraft Launcher (The last version I have launched from that profile is 1.21.3), it starts a Minecraft version with the version mark "Minecraft 1.21.3" on both the title bar and the bottom text. (Only the background has been changed to the scenery of Pale Garden.) The version mark in game is "Minecraft 1.21.3(1.21.4/vanilla)", which can be seen on the  Then I open the "Select World" page, and all the worlds created in 1.21.3 do not show yellow warning signs. Loading one of them does not show a warning page either. In the game, the features in Winter Drop remain in experimental options, and loading even a 57-pack-format datapack causes a "newer version" warning. Loading a 55-pack-format datapack causes an "older version" warning, and only the 56-pack-format (The pack format of version 1.21.2 and 1.21.3) datapack can be loaded without warning. There aren't any resin blocks in game, and the creakings generated by creaking hearts still have an id of "creaking_transient". In conclusion, the version "1.21.4" downloaded from Minecraft Launcher is totally not the version 1.21.4. It is 1.21.3 or 1.21.2.