Hi @mark_artos
Thanks for posting — this definitely sounds like some weird Edge behavior.
I’ve tested on this end using Windows 10 + Edge 18 and the cart functionality seemed to be working as expected.
Item in the cart
Item on checkout page
If you are seeing other behavior on your end, can you please share a screen recording of what you see? CloudApp or Quicktime work well for this.
Could you also please let me know what browser version you’re using by sending me your information from this page?
There should be a small share link when you visit the page which you can send to me.
Thanks!