Hello - I have an ArcPro project to which I have added several feature service feature classes and related tables from a client's enterprise server via rest services URLs. This server requires a VPN and a login, but I haven't had any issues with either of those. I am able to:
What I'm not able to do is see the spatial data on the map. There are no visibility range scaling restrictions on any of the feature classes. The enterprise geodatabase that I'm accessing has branch versioning enabled, although there are no branches other than the default at this stage.