Translating field labels simply doesnt work

1) Create a new fresh Drupal 8 instance
2) Create a content type (e.g. "page") and add a field (e.g. "field_phone"). Edit the label to be "Telefon" (i.e. German word for phone)
3) Now, add "English" as a new language under "/admin/config/regional/language"
4) Install the "Config translation" module if it isnt installed yet
5) Go to "/admin/config/regional/config-translation"
6) You should see the field you've created ("Telefon") in the list
7) Click on "Translate". You should see all the languages in a list. Click on "Translate" next to "English"
8) You can enter an English version of the fields' label. Enter "Phone".
9) Now, select "Add content" and select the content type ("page") from step #2. You can enter a title etc and of course the phone number.
10) Enter some digits and click on "Save".
11) You are now seeing your page. The title and "Telefon: 123456".
12) There is no way whatsoever to get this "Phone: 123456". Neithing by changing the URL from "/de/node/1" to "/en/node/1" nor by anything else I've tried.
13) ??? Whats going on here? IMHO if this is not a bug at the very least this is completely unintuitive. I think it's a bug.