There are so many solutions suggested for this same issue, but this is what worked for me. First I checked the NativeWind installation by calling verifyInstallation in my root component, like below :

// Ensure to call inside a component, not globally

verifyInstallation();

This gave me the error (on the emulator): "NativeWind received no data. Please ...."

Searching for this error led me here: https://github.com/nativewind/nativewind/issues/1050

and the solution near the end of this thread here was what worked for me in the end: https://github.com/nativewind/nativewind/issues/1050#issuecomment-2378814536.

I am quite sure I had once done this before also and it had not worked. But now it is working and finally I am able to move forward. Maybe this will help others too.