@AVerheecke I do not believe this to be due to Netlify, but rather a difference between what your project does for ng serve compared to ng build.
If I run npm run develop I see:
If I run npm run build && npx serve dist/collections-app/browser I see:
Unfortunately I can’t advise precisely how you should fix it, but it gives you an angle to investigate and you should find it much faster to debug locally than doing repeated deployments to Netlify.