Combine: what are those multicast functions for?

Using Swift
9

I changed my code to:

var validatedEMail: AnyPublisher<String?, Never> {
    return $eMail
        .debounce(for: 0.5, scheduler: RunLoop.main)
        .removeDuplicates()
        .map { username in
            return Future { promise in
                self.usernameAvailable(username) { available in
                    promise(.success(available ? username : nil))
                }
            }
    }
    .switchToLatest()
        .eraseToAnyPublisher()
}

but this didn't help the issue: the validatedEMail Publisher still works as expected but the validatedCredentials Publisher still doesn't fire if both other Publishers did.

So I opened

https://feedbackassistant.apple.com/feedback/6574579

@Philippe_Hausler