Strong password suggestion stopped working for registration in iOS14?

Question

I setup the strong password suggestion for my app registration and it worked fine, along with universal links. (Registration form is made with SwiftUI)

I now discovered that the strong password suggestion stopped working. The error message is:

"Cannot identify the calling app's process. Check teamID and bundleID in your app's application-identifier entitlement"

Which is weird because it worked all the time, also my Universal Links are still working as well as saving passwords to the keychain/associate domain.

Unfortunately I am not sure when it stopped to work exactly. It might have been after the upgrade from iOS13 to iOS14.

I checked the setup again:

1. Associated Domains in the app are set correctly
2. "apple-app-site-association" file on the webserver is valid
3. BundleID & TeamID are correct

What changed since it stopped working:

1. Upgraded to iOS14.2.1 (iOS14 is the Deployment Target)
2. App was released in the AppStore
3. My iOS Developer Programm renewed, TeamID stayed the same.

Here is the apple-app-site-association file i use and also worked all the time:

{
  "applinks": {
    "apps": [
      "1111111111.io.MyDomain.myAppName"
    ],
    "details": [
      {
        "appID": "1111111111.io.MyDomain.myAppName",
        "paths": [
          "/path/*"
        ]
      }
    ]
  },
  "webcredentials": {
    "apps": [
      "1111111111.io.MyDomain.myAppName"
    ]
  }
}

Anyone had the same problem and found a solution?