Why is my home screen background changing automatically?

[Android Central Question]

In the last week my home screen have changed by itself. I use a picture on my phone as a background, but my phone is changing to another picture i have.i have an samsung S8, please help i am going insane soon...

 

[Velenoso]

I had this happen to me when I had an S8+ but can't remember how to fix it, if you use a different lanucher I'd be looking in their wallpapers