If you want to stop your iPhone buzzing when in silent mode, head over to Settings > Sounds & Haptics, scroll down to System Haptics and toggle this to off. Duet Display: Turn the iPad Pro into a lag-free second monitor for Mac, PC. You shouldn't hear this when connecting your iPhone to a charger, and shouldn't affect charging at all no matter what device you plug your iPhone into, only data transfer. I have got a 4K external monitor to connect to my laptop, and have tried for. Even if I go into the display setting and try to adjust the colors, blue & all that is diplalying. This is a privacy feature that prevents USB accessories that plug into the Lightning port from making data connections with an iPhone, iPad, or iPod Touch if your iOS device has been locked for over an hour. When I plug in the display adapter to my second monitor the picture on the screen is blue. If you hear three buzzes or chimes, then this is a sign that USB Restricted Mode is enabled. For this to work, you'll need a compatible iPhone (officially an iPhone 8 or higher), USB-C-to-Lightning cable, and a USB-C charger capable of outputting a minimum of 15W, and for the battery to be discharged to below 50%.
If shortly (three seconds to be precise) after this first buzz or chime, you get a second buzz or chime, this means that the iPhone is fast charging.
