Next and previous button static image

[hapap]

Hello.

For some reason in my shop my next/previous or even number of page when i im inside a category list doesn't work,
See for exemple the URL: http://www.ribapedal.pt/5-estrada

If you on the bottom of the page try to click on "<" or "2" or ">", it doesn't do anything.

The most weird thing is if i have my browser window maximize, those buttons don't work, but if i shrink the window, they start to work.
What could make this behaviour?!

Edited September 24, 2018 by hapap
New information (see edit history)