Cells duplicated looking at mobile site

Hi,

I have created a table 3 x 3

Placed some images and a button in each cell.

Looks as expected on desktop looking on Google Chrome.

I checked on my phone Sony Xperia 5

The table gets pushed into 2 columns (no issue with this as it is a phone afterall).
But it duplicates some of the cells.

On main site on Google Chrome

Acoustic Products | Writing surfaces | Writing board – glass
Column board | Mobile boards | Projection Screens
Notice board | Accessories | <<< EMPTY CELL >>>

On phone it shows duplications.

Acoustic Products | Column Board system
Writing surfaces | Mobile boards
Writing board – glass | Projection Screens

Then a line

Acoustic products | Notice board
Writing surfaces | Accessories
Writing board – glass | TEST (will be empty cell)

How do we stop the duplication?

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