Is there a reason for any language to be listed twice in settings? By default, there is "English" but also "English (United States)".
And for both you can select "Display Microsoft Edge in this language". Does it make any difference? Which one of the two should be used for UI language? Is one of them more up-to-date than the other?
If you look at "Check spelling", you can enable this only for "English (United States)" while "English" is greyed out. But for German language it's vice versa, there you have spell checking for "German", but not for "German (Germany)".