Hi,
I had to check myself and the only difference I could see is that the layout of the pages doesn't display several columns properly on Safari.
So I suppose that's your problem.
This is linked to the fact that Safari doesn't support properly all the possibility of the Flex grid that we're using for the columns layout since a few versions of HikaShop.
This is something that was reported to us a while back and we did add specific patchs for that.
To solve the problem, HikaShop check the browser of the user and automatically load an extra CSS file for Safari which corrects the columns layout.
However, when I look at the HTML elements on your pages with Safari, I don't see that specific CSS.
What I can see is that you have JCHOptimize on your website which caches the CSS. So I think it comes from that.
You'll have to tweak the settings of JCHOptimize to take that into account so that the safari CSS file can be loaded when necessary.