transaction not found in receipt error received during iOS purchase

I am currently experiencing an issue that I cannot fully understand. I can verify that all the appropriate products are being queried successfully and I can view their entitlements. I can even initiate a purchase through the native UI's confirmation modal. However during the callback of the native purchase modal, I receive an error transaction not found in receipt. Is this a problem with my sandbox user, or is it a separate issue entirely? I can see within my Developer tools on my device that I do have an active subscription, but Qonversion is not reflecting the same results.

Any help would be appreciated, thanks.