how to remove the whitelines on my wordpress site

I did some changes to the background on the site and am seeing all these white blocks. How do i go about removing these white blocks.

https://preview.redd.it/tnqfqp2sjrrc1.png?width=1666&format=png&auto=webp&s=f7bc80056fe8d7de08aff356fe6e06e37283dfa3

 

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