NLooks like an infra setup issue
NOpen the network debugger and that request is returning a 304 and HTML
N
NYour vercel config is set up wrong, or the URL is wrong, it's redirecting back to the app when you click https://website-arthurdanjou.vercel.app/api/trpc/admin.isMaintenance?batch=1&input=%7B%220%22%3A%7B%22json%22%3Anull%2C%22meta%22%3A%7B%22values%22%3A%5B%22undefined%22%5D%7D%7D%7D
NYou have the same problem as before
NLook at the request in the network debugger
NtRPC is involved in this but you would have the same problem running any API with a bad vercel setup. Afraid I'm not a vercel hosting user though so can't offer much more than that