Hey @Matias_Corrao - happy to take a look into this and thanks for the details, based on what you’re seeing, it looks like the proxy is being forwarded to an invalid host, since the CLI output shows “Using URL: https://.trycloudflare.com/proxy” without a subdomain (unless you just edited it out there).
Normally, the Cloudflare Quick Tunnel created by shopify app dev should generate a full hostname (for example, https://abc123-test-tunnel.trycloudflare.com/proxy), so the empty hostname seems like there might be a misconfiguration or a CLI state issue rather than expected behavior.
Could you let me know if you’re using the current Shopify Remix template? Since you’re running app dev, it seems like it, but just wanted to confirm that. If you can also check the App proxy settings in your toml file that would be helpful!
If it currently shows https://.trycloudflare.com/proxy, replace it with your actual tunnel URL and retest to see if it sticks.
If you’re rely on the Shopify CLI-managed updates, try setting automatically_update_urls_on_dev = false in your shopify.app.toml and run shopify app dev clean to clear any temporary URLs before starting dev again. You could then switch it back to true to see if it generates the URLs as needed.
I also just wanted to share one of my colleague’s posts here that explains how Next Gen dev replaces URLs (including the Proxy URL) and how to reset your environment just in case it’s helpful:
If you’re still seeing those 404s/500s, just ping me here and we’ll dig deeper for sure. One thing that might help if you’re still seeing the issues is adding the -–verbose flag at the end of your shopify app commands, it can help us track down exactly what the app is doing and if you’re open to sharing those, that would be really useful! Hope this helps!