First thing I see, is that it’s scaling the design down when it uploads. My recommendation here is to design everything in a 12x20" artboard. This aspect ratio will be identified behind the scenes when you upload a file and scale things correctly (the SVG you uploaded uses no specified units, so it’s using pixels, and Illustrator uses a different value for pixels per inch than your browser does).
Second, it looks like it was maybe saved at 2 decimal places. This design is very, very small - where hundredths of an inch could make a difference. When you save as from Illustrator, I would use 3 or 4 decimal places.
Here is your same design that I saved back out using 4 decimal places. It seems to load appropriately for me.
livinghinge copy.svg.zip (40.5 KB)
New on the left, original on the right.
That fixed - there are a couple of areas that may not go as well as you planned.
This is the 6th hinge cutout from the bottom. It’s going to overlap the edge cut on the left. There is something like 3-4 ten thousandths of an inch between the two lines.