Something very weird is happening

I have a middleware that intercepts every request. Some of them have params like this /:id/:q.
but I can not retrieve that original string from url inside axios Incoming message because it seemingly contains only for example /2/boo. Is there any way to do that ?

I am sending an axios request from client side to the server side, which is failing.

I’m trying to receive Server-sent events (SSE) in the browser. My application uses axios (v1.6.8) to make API calls. This code (courtesy of this answer) works in node: