Why is the 'shopify theme dev' command leading to a 404 page?

Hello, I’m developing a theme for our webstore, and recently the link, which the command shopify theme dev brings up, leads me to a 404 page. It’s the same procedure I successfully used until ~2 weeks ago, any idea what could have happened?

There is the thing that I use GitPod, where global NPM installs are not preserved, so I have to run npm install -g @Shopify_77 /theme @Shopify_77 /dev everytime I fire up the instance, so maybe the Shopify servers detected some suspicious behaviour because the request comes from a fresh install every time?