Hello Aijones,
Welcome to Apple Support Communities!
We want to help resolve the issue causing your iPhone to restart at night.
Since you're using the current iOS version already, check for pending app updates that might be causing a software conflict: How to manually update apps on your Apple device - Apple Support
"Update your apps manually
On your iPhone and iPad, apps that you download from the App Store are automatically updated by default. But if there's an issue, you can update an app manually.
How to manually update apps on your iPhone or iPad
- Open the App Store.
- Tap your profile icon at the top of the screen.
- Scroll to see pending updates and release notes. Tap Update next to an app to update only that app, or tap Update All."
We hope this helps to resolve the software issue causing the restart/crash. Please also try a normal restart at this time as that might also help with this issue.
Cheers!