There are a few things you can check when you see connection problems (apart from the obvious question if UMP is running at address used).The challenge here is that there are no logs we can review to get a better understanding of the issue:
1) Please be aware that the iOS device needs to have a connection to the UMP server address, either by being on the same network or having a VPN connection to that network. Of course, if your UMP runs on a public address it should work as well.
2) Try to logon to the UMP via the mobile App with https disabled (untick the option on the logon screen):
3) verify that the ump_mobile package was deployed to the robot where the UMP (wasp) is running:
4)Verify that the mobile webapp is up and running on the wasp probe, and stop and restart it:
5) Open a browser on your iOS device and see if you can get to the UMP url. UMP is not optimized for display in a browser session on an iOS device but you should still get to the login is screen. If this does not work, you need to further investigate with your network team.