We are noticing an issue whereby when a guest user adds something to a cart, and then logs in during the checkout flow, and then adds an additional item, the wrong quantity is displayed in the cart.
We are not sure if the issue is related to the transitioning between guest and logged in user, or not.
We have seen this happen when either programmatically add items to the cart, or when a user manually adds items.
We are using Redis as the session cache.
Has anyone else seen anything like this?