Vue router history mode difficulty

I have been building a plugin at work to grab data from shopify’s storefront graphql api and build out some pages on our(my employer’s) platform.
Unfortunately I can only share the client side code from my project since the platform is proprietary.
But I suspect the issue is in my code/setup. When I change from default to history mode- (we use iis 10 and are already using url rewrite so it was easy to update the web.config file from the example in docs)- the app stops rendering.

As soon as I change:
Const router = new Vuerouter({
routes : [ …]


Const router = new Vuerouter({
mode : ‘history’,
routes : […]

All the components stop rendering (so obviously the routes dont work either)

The repo is here:
The main app js file is here:

It may be a little hard to read because we cannot import components so they all live in the same file together.

The router code starts around ln 541.
Im curious if the issue is related to the setup of our platform or maybe the use of .asp or my use of vue/vuex/vue-router.

The live example is here:

Thanks for any help!