not connecting to home wifi but can use wifi speaker. Is that weired?

[nongmoo2000]

Hello guys i just wonder. I bought B&O beosound2​ and connect it to my home wifi connection. My phone(mate9pro)​ can play song via my new speaker without connect to my home wifi ( turn off both wifi and bluetooth at my cellphone, but my girlfriens's iphone xs max cannot do that. Do you think it's weired to play song without connecting to both wifi and bluetooth??

 

[ElectrO_90]

Must be magic then.
Not sure how something that is NOT connected to wifi can access a wifi system.