I can't enable the repo rhui-REGION-rhel-server-rhscl for Postgresql95 installation

Hi,
I'm trying to install Postgresql9.5 in an instance of RHEL 7.3 with a subscription for Red Hat Developers. For this purpose, I have to enable the repository rhui-REGION-rhel-server-rhscl where is the package rh-postgresql95-server. But when I did

yum-config-manager --enable rhui-REGION-rhel-server-rhscl

not changes are maded. Any idea of how to enable this repository? The point is I tested this two or three weeks ago and it worked!

Thank you very much in advance.