Thanks. Deleting and reinstalling the app usually resolves most issues. If it does not, please reply back with the exact error message. Include a screen shot, if possible.
Do you see "VPN" at the top left of your screen next to the Wifi or LTE indicator? If yes, your device is configured to use a VPN.
If not, do you know if the router you're connected to is using a VPN? Because that would cause the same issue.
I have the same problem. I can't even get the app to load at all. It crashes before getting to the home page in most cases. I have IOS 11.4, app version 6.12. I see the VPN error when I'm swiping the app to close it. I've restarted my phone and nothing.