Upon further research, I found that IE11 doesn’t support Object.entries. As far as I could tell from looking at the massive minified jquery file, the lines with that code were near ecommerce stuff. It also looks like there are a bunch of json objects with parameters for animations at the bottom of the file, which makes sense because no animations were working on IE11. I also verified that no jquery events were loading under the events tab in IE11 on objects where they were loading in all other browsers.
I didn’t dig around much more than that, because minified js isn’t my favorite thing in the world, but I hope this gives a decent idea of what’s going on. Is there any fix for this, or at least an estimate for when webflow will be fixing this? For now, I’ve just been adding a bunch of custom code, which hurts my soul a little.
EDIT: As a side note, this issue appears to be closely related: IE11 Add to cart not working