Keyframes doubt

Question

In this code, I've used CSS Keyframes to make a changing background animation.

But after the 4th image (there are total 4 images and after that the animation repeats itself) when the 1st image shows up, overlaid by the 4th image.

To this problems comes up about after 20s from the start. I tried a lot of solutions but none of them helps.

Thanks for the help. 🙂

https://code.sololearn.com/WVYN128YouOD/?ref=app

Answer 1

https://code.sololearn.com/W7uMJiIWc5qi/?ref=app

Answer 2

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