I had a chat with my wife who is a teacher and an English as a second language qualified teacher and we both agreed that personnel is always a plural noun taking plural forms of verbs. The same doesn't apply to all words for groups of people however so for "team" we couldn't agree what the rules are for when/whether to use singular or plural forms of verbs.
As a US English native, and a TESOL teacher, I can add that we always say, "Your team is losing. Our team rocks!" So "team" gets treated as singular.
But "personnel" gets treated like plural. So the above sentence by Duo is odd, as you mentioned.
To answer Bart's question below, "staff" is used like "team". So you would common hear and say, "Your staff works hard. The presidential staff, on the other hand, doesn't."
Curiosity: "band" is also singular. "The band is getting back together."
More curiosities: The Dallas Cowboys (a football team) and The Beatles (a rock band) are always in plural. "The Cowboys are doing well this season." "The Beatles were famous." (I think this is because these teams and bands take on the grammar of their composition in language, e.i. the "s" in cowboys and bugs.)