Ionic 3 - Module not found: Error: Can't resolve '@app/env'

Building a new version of my app. Android and iOS built fine, but all of a sudden building browser fails.

Module not found: Error: Can’t resolve ‘@app/env’ in — some file
resolve ‘@app/env’ in — some file
Parsed request is a module
No description file found
resolve as module
looking for modules in — tries to find it in the node_modules folder its not there.

Have set up the @app/env in the tsconfig.json file.

“baseUrl”: “./src”,
“paths”: {
@angular/": ["…/node_modules/@angular/”],
@app/env”: [
“environments/environment”

environments folder has one for each build environment.
environment.dev.ts
environment.test.ts
environment.ts for prod.

Why this stopped working now doesn’t make any sense.
In code it finds the correct value, while compiling it breaks? Any idea?
Thanks

Any idea? Any idea how to test.

I’m using this setup