in app consumable purchase stay in pending state. never ends with success or failure

The app is in beta testing. I want to test the consumable IAP in the sandbox before pushing it to the external beta testers. however, the in-app purchase stays pending and never reaches success or failure. Also when I attempt to make a purchase, the purchase prompt closes with a success tone after giving the password but keeps appearing again. this is happening in a loop. I tried with multiple sandbox user accounts but no luck. any help here, please?

in app consumable purchase stay in pending state. never ends with success or failure
 
 
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