how is iphone 15 pro max still findable after switch off/ turned off

My concern is HOW Apple SAID IT's FINDABLE when it's turned off and when it was stolen. it didn't work and i couldn't detect its location.

In order for the phone to be located, there must be other iPhones in close proximity to pick up the signal that the iPhone is still sending out even though it has been turned "Off".

That condition is not currently being met. And, Of course, the battery will run down after a few days, so no signals will be sent after that occurs.

Yet your phone might still show up if the conditions around the phone improve in the next few days.

Also keep in mind that iPhone thieves are very fond or placing a stolen phone in a special type of bag that will not allow the phone to either send or receive a signal. That may also likely be a factor here.

I'm sorry, but you have to realistic about things. The chances that the phone will ever be found are a tiny fraction above zero. Phones that are "found" are those left in a friend's car, a friend's apartment, or a restaurant or shop with honest employees.

There are few reasons that the iPhone shows unknown location , one you already leave the iPhone with no internet services and other reason that’s off is because the battery of the iPhone drains its power it will be located when the iPhone it’s on , to understand the findable meaning it’s when the battery it’s charged while iPhone it’s off