Payment not Complete right after CompleteMerchantValidation

We hav implemented Apple Pay for our project , Merchant setup etc. are properly done and we are able to see the Apple pop-up in the website , however the Payment cancelled is getting triggered after CompleteMerchantValidation event , due to this we are not able to see the final payment button

Verified Certs, Merchant details as mentioned in the thread https://forums.developer.apple.com/forums/thread/689956 , however no luck , no error seen in the console.

Any pointers to fix this is appreciable , thank you!

Payment not Complete right after CompleteMerchantValidation
 
 
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