Chosen Solution
When turning on the phone, the apple logo appears and then it goes black again, and the logo appears again and then it turns on. Does the apple logo always appears 2 times before turning on? Back to my question, the phone restarts after a while, the screen freezes and it restarts. Sometimes even when I’m not using the phone, it restarts itself. Please help.
Yep when turning on the iPhone it’ll flash the apple logo two times before it starts, not sure why they added that but it first started when iOS 11 came out. Are there any other present problems with the phone other than the phone freezing and rebooting itself? What does the battery health feature in the settings report for percentage? Does it also happen when it’s near full charge and plugged into a charger? Has the phone been serviced recently? Random restarts can be caused by a bad battery, phone being liquid damaged. One of the things I recommend trying is restoring the phone via iTunes or 3UTools, make sure to backup the phone before doing so as it factory resets the phone resulting in wiping information / data and see if that solves the problem.