Your Server configuration is not restrictive with respect to cross-origin requests, hence the message you see comes unexpected.
We may even suspect that some intermediate node provided an error response on behalf of LS Server.
We should see the related full HTTP request and response to ascertain that.
Please also clarify if you now see this issue always.

If I understand correctly, you feel that this issue may be the cause of your app hanging on Chrome, but you have no more information to share on that episode.