Doesn't sound right. Are you on the latest firmware and how often does this happen to you?
Are you willing to share a bug report with us next time this happens?
Please generate it right after the issue appears
To generate a bug report you need to
1. Enable developer mode by going to system --> about phone --> software information and click on build number a couple of times until you are a developer.
2. Go back to system --> Developer options --> Take bug report --> interactive report
Save the report to your google drive and share the link with me via private message. Please also make sure that everyone with the link can view the file so I can pass it on to our developers.