hey, i'm hoping someone can help because i'm stuck regarding API requests having different behaviour on dev vs prod

i have my API (using ORPC routes) deployed on Railway and my frontend (React + TanStack Query) deployed on Vercel. In development everything works fine: react requests the API and gets proper JSON responses.

but once deployed, the frontend’s requests to the production API come back as HTML/File blobs instead of JSON. The strange part: if I open the production API URL directly in the browser, I do see the correct JSON. It’s only the frontend fetches that receive HTML.

a friend suggested this might be a Railway quirk where requests from the website somehow get routed incorrectly, but we aren’t sure. also thought it might be CORS-related; i tried updating CORS to include localhost, my domain, and the Vercel-owned domain, but that didn’t fix it.

has anyone run into this issue or know what could cause the frontend fetch to return HTML while direct browser access returns JSON?