Component used: Navigation
Version used: 2.4.0-beta02
Devices/Android versions reproduced on: Pixel 3 API 31 emulator, Pixel 3 physical device with Android 12

When you pass an optional value that is equal to its key name the value gets lost and the NavBackStackEntry reveives null (or default value if it's set). If any other value is passed everything is correct.

For example when I navigate to route secondary?param=param the param value turns into null on the receiving end. I guess some internal parsing is messed up.

I'm attaching a sample project showing this issue.