My launcher background won't change to the new one

Hello Mojang, i have a bug with my Minecraft Java edition Launcher. The 1.17.1 update is out now, but my background of the 'Play' screen won't change to the new background, i still see the background from 1.16, the Nether update. I play on MacOS, but my MacOS is a bit old, he's on version 10.9. But, i can play 1.17, but my background won't change. Can you please tell me how to fix this?