Xamarin InAppBilling showing ItemUnavailable for purchase on Android - xamarin

Question

I'm implementing the InAppBilling plugin in my Xamarin Forms 5 app for auto-renewing subscriptions.
I have the "subscriptions" set up on Google Play and they're active. When I ask for a list of subscription items, I get the list fine but when I try make a purchase, I get the following error that indicates the item is not available.
I'm running this on a real device connected to my laptop via USB. Any idea what I'm doing wrong?
Here's my purchase subscription method which is directly from documentation here:
public async Task<bool> Subscribe(string productId)
{
var billing = CrossInAppBilling.Current;
try
{
var connected = await billing.ConnectAsync();
if (!connected)
return false;
//check purchases
var purchase = await billing.PurchaseAsync(productId, ItemType.Subscription);
//possibility that a null came through.
if (purchase == null)
{
//did not purchase
return false;
}
else
{
//purchased!
if (Device.RuntimePlatform == Device.Android)
{
// Must call AcknowledgePurchaseAsync else the purchase will be refunded
//await billing.AcknowledgePurchaseAsync(purchase.PurchaseToken);
}
return true;
}
}
catch (InAppBillingPurchaseException purchaseEx)
{
//Billing Exception handle this based on the type
throw new Exception("Error: " + purchaseEx);
}
catch (Exception ex)
{
//Something else has gone wrong, log it
throw new Exception();
}
finally
{
await billing.DisconnectAsync();
}
}
As I mentioned before, I see the subscription items available and active on Google Play. I also made sure, I'm getting them from "Subscriptions" and NOT "In-App Products". I'm using the ID that I copy and paste from the "Product ID" column on Google Play Console -- see below:
Any idea what the issue here may be?