Deep linking not working unless app launched

[crspybits]

When inviting someone to use the app, and you first install the app, then tap on the email link, the appropriate modal doesn't open after the app opens-- unless the app is already opened first. See also https://stackoverflow.com/questions/45089559/unable-to-pass-in-params-w-sms-deeplink-on-ios-11-when-ios-messages-is-not-a
This appears to be an iOS11 issue.

[crspybits]

This is arising due a delegate method not getting set at the correct time. See my comments on the above SO link. I could make a change in my code to fix this-- However, I'm not sure if Apple is going to fix this.