The app has a per-shop pickup lock called hideOtherDeliveryWhenPickup.
When that lock is enabled and a pickup point is selected, the delivery customization hides rates that deliver to an address.
The selected pickup rate remains visible.
Local pickup remains visible because it has its own destination.
Cash-on-delivery for the same selected point remains visible.
The lock does nothing when no pickup point is selected.
The lock also stays off when the pickup rate itself is already hidden, so checkout is not left without a shipping option.
When the lock is not enabled for the shop, courier rates stay visible after a point is selected.
What to ask support to check
Ask whether hideOtherDeliveryWhenPickup is enabled for the shop.
Ask whether the buyer had already selected a pickup point in the cart before reaching checkout.
Ask whether pickup visibility rules are hiding the pickup rate itself.