Facebook so slow to react on Safari

Hi all, wondering if you can help.

I have a Mac Mini late 2012, i5, 16gb ram and a 500gb SSD.

Using Safari, on Facebook, if I click a group link in my favourites, it takes 1 to 2 seconds to act upon the click, if I right click and select open in tab/window it's pretty instant.

I'm presuming it's something to do with Facebook/Safari combo as Safari works fine for me on 98% of other sites and Facebook works fine for me using Opera (my second choice of browser)

I've tried turning off adblock and pop ups, but still the same.

Can anyone help at all?

Thanks