Samsung occasionally locks down their devices to only work with a limited number if chargers. A charger may perfectly implement qualcomm quick charge, power delivery, or standard fast charge and still not work properly on a Samsung device.
Samsung desperately wants to be Apple and closer their devices to third party accessories, including chargers. Samsung makes excellent hardware then makes crappy, convoluted software, and hardware limitations to prevent consumer choice. I may have to return my Galaxy A71 because it does not play well with the same chargers that have powered my Galaxy S8 for three years. I only chose the A71 for the large battery and quality camera.
Time to try another brand.