Mobile SSO doesn't work on iOS when using Microsoft Authenticator App for MFA


I'm using the IdP Mobile Forge component for mobile SSO with Azure AD. 

I've been having a problem with iOS in the production environment when switching between my app and the Microsoft Authenticator App for MFA. On switching back to my App they get an error from IdP Mobile  "Error loading https://sts.company.domain/adfs/la/?client-request-id=......."

The steps they use are:

 1. Go to app. 

2. Click login with AD account

3. Enter email address, 

4. Enter password for ad account, 

5. Tap on Authenticator App notification, switched to Authenticator 

6. Tap Approve

7. Switch back to the app.

then get error "Error loading https://sts.company.domain/adfs/la/?client-request-id=......."

I have not been able to replicate this on Android or any Ad-hoc and development builds and other MFA methods such as a phone call or SMS have no problem. It only happens on iOS with the App Store version of the app which is the same version as Dev. And only when you switch to Authenticator while it's loading. 

Instead of tapping the notification, you can pull it down and tap approve, then it will login fine. 

If I switch to Authenticator, then switch straight back, my app gets the error right away

Switch to some other App and then back the page is still loading. 

Edit: Switching to some apps and back will cause the error. I suspect apps that use the network are causing this.

Thank you.