Why not << Soyez content. >>, how do we know it's a plural vous?

Why not, 'Be content'? Reported.

Why is "contents" with an s: "be happy" can also be said in singular form, in which case "soyez content" should be considered correct.

Why not "be content"?

Can't even report it in the "Type what you hear" exercise!

No difference in sound with soyez content and soyez contents but the former is marked incorrect.

Not accepted, but is "Be satisfied!"also a good translation?