Okay so UberEats has a ridiculous interface and I've just figured out how it works. For some incomprehensible reason, the app receipt does not show your discount at any step. The physical restaurant receipt also did not show the discount and showed the full undiscounted price. During checkout, I checked my bank account and the pending charge was for the full undiscounted price. However, after checkout at some point, the actual charge is then updated with the discount. My bank account shows the discounted charge pending now.

Why, UberEats... This is unacceptable nonsense in the world of modern apps.