Why does excel constantly recalculate when I change something minor?

This started happening years ago but its driving me particullary crazy today.

A few years back something changed where when I would make even just the most minor change, all formulas in a spreadsheet would recalculate. For example, if all I did was change a cell color to red, I might be sitting there for 30 seconds waiting (even if the cell I'm recolouring is empty).

It's just happened again. I have a page with 4 columns of sumifs in cells E to H (which I know are quite heavy on calculations) but all I did was delete a few cells from my table all the way over in cells K6 to R13 (I essentially removed the top row) and now I've gotta wait 10 minutes for all my sumifs to recalculate again even though I've not touched them at all.

It never used to do this so I dont think its a 'well thats just how excel works' so something must have changed. Is there a setting I can use to stop this happening?

Thanks