Apple-App-Site-Association (AASA) behind VPN but Phone is in VPN

My apple-app-site-association file is hosted on an internal dev server that's only accessible through VPN. The Cisco VPN on my phone is turned on. My AASA file includes webcredentials service and i wanted to implement password autofill feature for my application. I am opening the login page using Webview, and also have set correct autocomplete attributes for my password and username input fields. But autofill is not working for my app.
I also tried bypassing the CDN mode by using "alternative-mode" and setting it to developer in the associated domain entitlements file.
Also ,For the developer mode I allowed the bypassing in the Settings App -> Developer. I am currently installing the APP on my test device using Xcode.

Please could you help out in knowing how I could debug this, and check whether it is related to AASA file not being downloaded or anything else.
Apple-App-Site-Association (AASA) behind VPN but Phone is in VPN
 
 
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