IAP not working the second time

I am building an app for quest in unity.

I have integrated the Oculus Platform SDK & made all the requirements according to the documentation.

When I run the app and purchase the consumable purchase for the first time, the purchasing is successful.
But for the second time it gets stuck and the callback is never called.

While waiting for the callback if I press the power button on the headset & hit cancel on the power-off popup, then it automatically goes back to the app and purchase gets completed and and waiting callback finally gets called.

Don't know hot to over come this issue. I have checked out all the possible solutions on the forum, but can't found any.

Is this a problem within the SDK?