All links work for me, I will try this method soon in a Matepad 11
1. Download the ZIP file (if the links are no longer working, let me know)
I have the same problem, i bought it in Europe the RMX1971 with ColorOS6 RMX1971EX_11_A.09
We didnt recived RMX1971EX_11. A.11 update yet... (29th October 2019)
Maybe thats the reason the app to unlock bootloader doesnt work.