Assets\Scripts\xxxx.cs(24,23): error CS0246: The type or namespace name 'xxxx' could not be found (a

When I build to Quest 3 I get errors such as

Assets\Scripts\xxxx.cs(24,23): error CS0246: The type or namespace name 'xxxx' could not be found (are you missing a using directive or an assembly reference?)

I am able to work in play mode but the build to Quest 3 fails
The packages are installed and I checked the manifest.json and the dependencies are there