Home page posts are repeated

Hello,
we are using the theme "dw-timeline-pro".

After making some changes emerged a very strange problem, that we can not solve.

Home page posts are repeated.
If I set 3 as the number of posts in the settings reading wordpress, I see:
last 3 post, then again last 3 post and then again last 3 post.
It ‘a problem of pagination, it seems.
Each page contains only the last post and not the next.

I understand that you do not provide this type of assistance, it depends on when we did some customization. But I saw that even in a old your fix concerns an argument and maybe we can help.

Thanks in advance and good day