User can subscribe multiple times and break site functionality

[KamilTheDev]

Once a user is subscribed, the pricing buttons change to "Manage", which infers it should now take them to the customer portal to manage their subscription.

However, instead it takes them to the same page to pay for the subscription again. The user can subscribe to multiple plans, and once they're subscribed to more than 1 plan, the site is acting as if they have not subscribed at all (while the stripe customer portal correctly shows their 2+ subscriptions).