Beginner Issue with D3500

[JulesD3500]

Hi there! I use my Nikon D3500 in low light conditions and always on the Auto no flash setting. Been great for 2 years, but in the past few days, I find that pictures taken in low light on AF no flash have a red noisy strip along the bottom left corner. Could there be an issue with the lens? I have added an example picture as my profile picture/avatar on here. Thank you!

 

[john.margetts]

I would think it is more likely to be the sensor.

 

[TCR4x4]

The image is too small to see anything, but it won’t be the lens whatever the issue is.
Either light leak through the viewfinder or the sensor is having issues Maybe.
Post up a full size image with the problem on here and might be able to narrow it down more.