I really do think Duolingo should distinguish "ihr" from "du/Sie." Ihr is plural, and to make it cleaner for English speakers that don't have a formally recognized plural form of "you" (excusing local y'all and yous), simply using "you all" would inform those of us to the difference between du hast (you have) and ihr habt (you all have/y'all have/yous have).
Essen is not used as “are eating.” They are two different words.
all nouns are capitalized: Buch, Tasse, Kaffee, Katze, Brot...etc. So Essen (capital E) is the noun, “food”.
The word essen (not capitalized) is the verb “ to eat”. ich esse = “I eat, I am eating.” du isst = “you eat, you are eating.” sie/er isst = “she/he eats, she/he is eating.” wir essen = “we eat, we are eating.” ihr esst = “you (plural, informal) eat, you are eating.” Sie / sie essen = “You (formal)/they eat, you (f)/they are eating.”
That’s how it works.