Unable to set CORS with codespaces

I have 2 different urls for the server and the client:
client: https://name-codespaces-os-53764g-3000.githubpreview.dev/
server: https://name-codespaces-os-53764g-3500.githubpreview.dev/

When I apply cors from the server to the client somehow the headers are not being pass back to the client.
This is a mature app that works on local and production with cors.

Can codespaces overriding my cors settings? if so, how can I overcome that?