Analyzing some orders workflow to a client we saw that in some orders the gift card code wasn't generated, so I decided to share here the solution that might help you too.
ReadThere are some issues that might cause the stock inconsistency issue, but before anything make sure you're running the most updated version of the MSI in your current Magento 2 installation, you can update it via Composer even not updating the entire Magento 2 installation.
Read