iOS 11.3 battery issues on iPhone 8

hello,

2 days ago I updated my device to iOS 11.3 (before, i had 11.2.6). after updating to 11.3 my battery usage is so much and can't use my device like before, for example, I turned off WiFi, Bluetooth, and mobile data, locked my phone and after 5 mins, I lost 2% !!! Checked battery health in setting and my battery capacity was 96% which is normal I guess, is this a global issue or just mine? to be honest afraid of using phone and turned of 'till get a solution.