.map & .js will not generate at all for the src folder after initial build

[TomasKatz]

Looks like source maps are created only for first build then in sequential builds it will not build new .js & .map files leading to errors.
The config is built quite straight forward and I cant understand why this happens.
But for example deleting the .js/.map files manually and then running build again will not re-create the .js/.map files , the only files that are created are the dist bundles.
I have posted a very detailed question about this issue on stackoverflow you can read it here.