How to Prevent Item Stock going to under 0

Hi everyone,
I am using Woocommerce for selling some digital products. Due to the natural of our business, we do not want the item stock to go lower than 0 (-1, -2, etc.)

We are currently accepting different payment methods, including Cryptocurrency and Stripe. As the transaction speed of Crypto is low, sometimes takes up to 1 hour, so we are facing issue like this:

1. When an user (User #1) purchase an item and pay with Crypto, the item stock gets hold (going from 1 to 0). As the blockchain is slow, it takes 2 hours to complete the payment. Since it’s so slow, the item stock goes back from 0 to 1.
2. While the blockchain payment is still pending, another user (User #2) comes to buy the same product. At this time, the item is not being held anymore. Thus, this user gets the product. Item stock goes from 1 to 0.
3. The blockchain payment is finally confirmed. Woocommerce also gives the product to this user. Item stock goes from 0 to -1.

So 2 users get the same product.

How to prevent this issue?

Thank you a lot!