Not sure how to help with this issue, maybe it's a rougue process/app that's causing the problem. If you are concerned about device security and malware, what I would do is go to the app store and download Malwarebytes Security: Virus Cleaner, Anti-Malware. It should have 10mil+ downloads and close to 300k reviews. It takes up quite a bit of battery so you can delete it soon. Just do give the necessary permissions and do a full scan. Good luck with your problem!