I had the same issue. It’s because of the missing browserslist config in your project.
If the Angular CLI compiler doesn’t find a .browserslistrc file or a browserslist config in your package.json it will use the default config from the browserslist project.
At the moment (v 4.16.6) this is
> 0.5%
last 2 versions
Firefox ESR
not dead
which includes ie11-support.
I would recommend you to a add a .browserslistrc, in the root direcotry of your application (meaning in the same directory as angular.json) with a default config. f.e:
last 1 Chrome version
last 1 Firefox version
last 2 Edge major versions
last 2 Safari major versions
last 2 iOS major versions
Firefox ESR
not IE 11 # Angular supports IE 11 only as an opt-in. To opt-in, remove the 'not' prefix on this line.