Review on 2 Pack Samsung USB-C Super Fast Charging Power Adapter-25W PD Charger Block for Galaxy Note10 S10+ S20 S21 S9 S8,iPhone 11 ProMax Xs Max XR X, iPad Pro, Google Pixel 2 4 3a XL, LG and More - Efficient Charging Solution by Barb Gordon

Not sure if that's mentioned anywhere but these aren't genuine Samsung fast chargers, they're fake. As far as I can tell they work exactly the same and don't feel inferior at all. Both worked 100% on my Galaxy S8+ but neither of them can fast charge my Galaxy A11. I believe the problem is that the A11 cannot verify the authenticity of the charger, while the S8 most likely would not attempt to verify this. Just something to note.