I can replicate the issue and it seems it is just the way it is. It flashes but .dmg is mounted, just check the mounted drive/folder.

I tested on the older version of Bitcoin Core 24.0 the dmg installation file also flashed, but on 23.0 the drag-and-drop installation method popped out.

So make sure you unmount any currently mounted Bitcoin Core installation drive, to make sure you did not mistake it with the older version, then click the dmg and check the mounted drive.