Thin horizontal line on home screen
iPhone 6, null
This may indicate hardware issue. Try some basic troubleshooting steps:
Try to reset your device. This won't delete your data stored on this device.
Alternatively, you may go to Settings - General - Reset - Reset All Settings
If this does not help, restore your device to factory settings. Note that this will erase the data from your device.
Take a look this Apple Support article: Use iTunes to restore your iPhone, iPad, or iPod to factory settings - Apple Support.
If it does not help take your device to the Apple Store for further diagnostics.
Thank you. I have done a Settings > General > Reset > Reset all settings and will note if this issue appears again.
You are always welcome.
Thin horizontal line on home screen