Possible issue with headers and authentication

Hello!

I'm not sure is an issue of this library but it could be so here it is what I'm stuck in:

I'm using https://pub.dartlang.org/packages/stomp as a communication protocol but using web_socket_channel as websocket library because theirs have problems in Flutter.

With no authentication everything seems to work fine. The problem appears when I try to set a User header (bear with me here I'm not an expert on websockets) it seems that the websocket client library does not keep sending that header.

Since I might be confusing things, here is an example of the problem. As you can see this is the answer sent from the server to the client in flutter after the connect where I've authenticated the user and set it in the headers.

Here you can see the next action (subscribe) sent from the client (flutter) to the server where the client header does not appear again.

In order to discard the possibility of a bad configuration on the server side I've tested this with a javascript client and it worked well.

Any suggestions of what could be happening here?

Thanks!