The SDK doesn't automatically rebuild U# code after switching platforms.

As a result, if you enter Play mode immediately after switching, the code from the previous platform is executed (e.g., code inside #UNITY_ANDROID preprocessor directives when switching from Android to another platform.

Workaround:

To fix this issue, I currently make a small change in the code, such as adding an empty space, to force a rebuild before entering Play mode.

Edit : This seems to only happen to me when I switch from Android to Windows.