As we noted back in September, iOS 11's Control Center buttons don't actually turn off Bluetooth or WiFi, unlike previous versions. Instead, tapping on either one simply disconnects you from any devices or services your iPhone is currently connected to. Apple ostensibly made this change so that you could stay connected to other services like AirDrop and devices like your Apple Watch. Still, the behavior can be confusing to many. According to MacRumors, the latest iOS 11.2 beta gives you an explanatory notification when you tap either Control Center button.
According to screenshots, your iPhone will show you a notification like the following: "Disconnecting Nearby WiFi Until Tomorrow" with an explanation about how the current network and others nearby will be disconnected until the following day. It also states that "WiFi will continue to be available for AirDrop, Personal Hotspot, and location accuracy." You'll see Bluetooth in the notification if you tap that button. This third iOS 11.2 beta comes a week after the second beta, which includes Apple Pay Cash via the Messages app and a few days after Apple released iOS 11.1.1, which fixed an annoying autocorrect bug.