After having updated my flow-bin package from 0.142.0 to 0.143.1, I got hundreds of error messages like this one (signature-verification-failure):

I know this version of flow made types-first the default mode but still, I don't understand since all of my functions are properly annotated, like in this simple class:
/* @flow */
export class Foo {
bar = (n: number): number => n + 1;
}
I also tried export default Foo and module.exports = Foo but got the same result.
What am I missing here?