8plus switch on automatically when charging

Here’s the question, I just sign the 8 plus package from Celcom last week, and I shut down the phone and wanted to charge, it turned on automatically after connecting with plug in the usb cabel. This is my first time using iPhone, so I’m not sure it’s normal to be happened on iPhone or not, it’s not the first time happen like this.. so I went to ask my iPhone user friends and showed the incident in front of them, even they said it’s not normal.. it should have showed the battery bar when charging in off situation.. so please do assist me do I need go back to apple store for further assistance?

One more thing, the WiFi and Bluetooth always turn on automatically without my acknowledgement. **** men 🙄🙄