Google smart lock across multiple apps not work

Question

we are trying to enable automatic sign-in across apps and websites in our app according to the doc

Currently, we have done

1. Added the content related to our app to the Digital Assets Link JSON file
2. Added asset_statemenets to the manifest file
3. Added asset_statements string resource to the strings.xml
4. Published the app in google play store (100% rolled out)
5. Applied Smart Lock for Passwords affiliation form serval times, but haven't gotten any response. The last time we submitted it on 10/16

But the latest app still can't get credentials shared by other apps listed in Digital Assets Link JSON. Is there a way to know the credential linking progress? currently, we don't know what's going on and can't know what issue we are having.