Can't seem to get Hot Module Replacement working in a Dockerized environment

My company is using Vue on the frontend, and Docker to run our environment. npm run dev works but not watch or hot. If I run watch files will be properly compiled but the browser won't refresh. If I run hot The app breaks, and I get these errors in the console:

Loading failed for the <script> with source “https://localhost:8080//js/manifest.js”.
Loading failed for the <script> with source “https://localhost:8080//js/vendor.js”.
Loading failed for the <script> with source “https://localhost:8080//js/app.js”.

The repo isn't public but I have gists of what I think the relevant files are:

Here is the webpack.mix.js file: https://gist.github.com/wishinghand/fd185d76079024ee07d37e48836fdbc6

Our docker-compose.yaml: https://gist.github.com/wishinghand/be5b6328665f92b2bd26d68f3bbe08dd

And most of our .env file (sensitive info is removed): https://gist.github.com/wishinghand/a504e4a7f7221209a9e7be2d543a1cf5

I noticed the .env file is using port 8080, but if I change it to 8081, I get the same errors I listed above.