overlapping posts

Hi, I’ve recently just completed my portfolio using Cenote free version.
Everything has been great so far, though the posts (project page) often overlap with each other – such issue would appear with about 70% of the chance when first opened the page (same thing happened too when opening the page with mobile phone), and happened very frequently when changing to next page.

Such issue often happened for the first two rows or the last row, I’ve tried different settings – changing the sizes of featured images, the numbers of posts showed in a page, making the sizes of featured images the same – but nothing has worked so far. It would return to normal when the page is refreshed, but would appear again if i come back to the page, go to next page or go to another tag/category.

here’s a screenshot to what i mean by ‘overlapping.’

View post on imgur.com

Please help… any suggestion is appreciated.

The page I need help with: [log in to see the link]