When you open an HTTP service from the Portal, it correctly opens in a new browser tab, but the new tab is then immediately closed.

The IXON Cloud is likely being displayed by an external party in an iframe. Recent browser updates contain security updates where any authentication done in an iframe is contained within the iframe. In other words, when an HTTP service is opened from within the iframe, the new tab cannot check if you have access to the HTTP service, because the new tab is not allowed to check the authentication that was done in the iframe. As a result, the authentication check fails and the new tab is immediately closed.