Checked through the interactive check the line doesn't show on that but the picture itself like to be zoomed in. Looks like the line is in the portion that is was cropped and zoomed in on. Cleared Cache and reset camera settings and line still there.
As you have performed the camera settings reset and it didn't fix the issue, last option would be the Factory data Reset. Please backup your device data using the Smart Switch and then perform Factory Data Reset.
The Samsung Smart Switch Mobile app seamlessly transfers contacts, photos, music, videos, messages, notes, calendars and more to virtually any Samsung Galaxy device.
You can also backup data using Smart Switch to your computer (need to download and install Smart Switch on mobile and computer) by connecting the device to a computer using USB cable and follow the on screen instructions.
Note: Factory data reset which deletes complete data from the device. This will restore your smartphone to its original manufacturer settings.
From phone Settings>>Global management>>Reset>>Factory data reset>>Scroll down to the bottom and tap on Reset>>Confirm that you understand about all data being lost and cannot be recovered. Tap on Delete All.
If the issue persists, your phone needs to be examined by an authorized technician.
Please note: Due to COVID-19 precautions, Service center operation hours may be impacted considering the local situations. Kindly call the service center before your visit.