This fetch request sends "application/json" as ContentType on IOS but "application/json; charset=utf-8" on Android:

fetch(url, {
    method: 'POST',
    headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json',
    }
})

The server I'm working against requires application/json and fails when charset is added. I've filed a bug report with them too, but shouldn't fetch behave identically on ios and android?