Unable to stream Amazon Prime in HD since their release earlier this year, the Redmi K20 and K20 Pro are no longer stuck in the mire of standard definition. While Xiaomi stated in October that it was working to address the issue, it seems that the fault may have lay at Amazon's door instead.
https://www.notebookcheck.net/The-Redmi-K20-and-K20-Pro-receive-a-surprising-update.448098.0.html