Products are disappearing from the cart when I navigate between categories!
If you are using the WooCommerce Protected Categories plugin, then your customers can only buy products from one password protected category at a time.
If a customer enters the password for one category, adds products to the cart, and then logs into a different password protected category, then the products from the first category will be removed from the cart. This is because it is only possible to unlock one password protected category at a time. By logging into the second category, the customer no longer has access to the products in the first category, and is therefore unable to purchase them.
If you don't want products to disappear from the cart when you navigate between categories, then we recommend structuring your protected categories in a different way. It's not good user experience to expect customers to enter multiple passwords as they navigate between your categories. Instead, create a main 'parent' category, password protect it, and add as many sub-categories as you like. Leave the sub-categories set to Public, and they will automatically inherit the same password as the parent category. That way, customers can navigate between categories without having to enter different passwords - and as a result, the products will not be removed from the cart.