My oneplus 3 got this problem from last 2 days, i have unbrick my phone with
Magic Unbrick tool for oneplus3. Even after that problem still persists
Step 1: Unbrick Phone with mega unbrick tool for oneplus 3.
Step 2: After unbrick, start phone normal, if problem still persist, download lastest rom from oneplus store.
Step 3: Flash latest rom to oneplus device with side load.
Hope this works for you too!