I work as the end user compute engineer at my employer. My test managed shared iPad Pro was on iOS 18.0.1 and from the sign in screen I was able to double click the lock/wake button twice to open the Wi-Fi picker. I upgraded it to the latest iOS 18.1 update and the Wi-Fi picker screen no longer comes up when double clicking the lock/wake button. Has this feature been removed? If so, this will pose a huge issue when it comes to new users signing in when not on a known Wi-Fi network.
For help with WiFi picker, please post in the Apple Support Community. The Apple Developer Forums are for questions about APIs and features intended specifically for developers.