Ever since last weeks 18.5 beta update, the Deltek Vision T&E app no longer opens. I did the next update last night, still not working. I've deleted the app, restarted phone, re-installed, still the same behavior. When you open the app, it just spins and nothing ever happens, don't get to login screen or anything.
When Apple release a new beta and an app doesn't work, it's likely because that app is doing something that has changed in the new beta.
It is up to the app developers to make their app work with the new version of iOS.
You should get in touch with them, not us. (We're not Deltek developers, and we don't work for Apple.)