3 column grid layout not displaying in Internet Explorer

Hi
My website is https://www.30thwarringtonscouts.org.uk

Thought I’d got this all finished and discovered another problem which I’m at a loss of how to resolve. Any advice would be appreciated.

I’m using the 3 column grid layout on my home page. This all looks beautiful on Google chrome then when I happened to look at the site in Internet Explorer 11 the front page is all screwed up.
It shows 2 columns on the left and the third column (which should be on the right hand side) is on the line below in the 2nd column. This pattern is repeated on the next line.

Sorry if this is something obvious, but I’m no expert in this.
Any help gratefully received.
Kath

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