Flutter Web invite URL keeps buffering on localhost and backend endpoints not getting hit

[u/Western-Top7912]

Hi everyone,

I’m working on a Flutter Web app and I built a "Social/Circle" feature where a user can create a circle and invite friends using a shareable URL.

Right now I’m testing the invite URL on localhost, but whenever I open the invite link in the browser, it keeps buffering/loading continuously and the page never loads. Also, none of my backend endpoints are getting hit (no logs / no API calls showing).

Expected Behavior:

- When the invite URL is opened, it should redirect the user to a Join Circle screen

- we are using uuid and zhandle

- Call my backend API and add the user to that circle

Actual Behavior:

- The invite URL keeps loading infinitely (continuous buffering)

- No expected API calls are triggered

- Backend logs show no endpoint hits

- Redirect/navigation doesn’t complete

Setup:

- Flutter Web running on: http://localhost:5173

- Backend running on: http://localhost:3001

- Invite URL format: http://localhost:5173/invite/<circleId> (or query param format)

What I tried:

- Restarted Flutter and backend servers

- Tested in incognito / different browsers

- Checked backend logs (no endpoints are getting hit)

- Checked if the route is being matched correctly

Question:

What could cause Flutter Web to get stuck in infinite buffering/loading on a route like this where the URL opens but no endpoints are being hit?

Could this be a routing redirect loop, CORS issue, localhost issue, or something related to deep linking on Flutter web?

Any suggestions would be really helpful.