Some users have reported that booting phone with charging on is solution.
I have a cable issue but original cable has always worked for me.
Tested with ampere apk.
Did you order cables too?
Aukey charger comes with proper cable if you order that bundle.
Quick charge 3 does not work all cables. Original cable (comes with phone) works ok.
Test original cable, charger and ampere. Boot your phone with charging on. Tell the results here.
edit. read this https://xiaomi.eu/community/threads/quick-charge-3-0-problem.43049/
https://www.digitbin.com/unlock-bootloader-xiaomi/
You need ask permission to unlock your phone. Xiaomi will send you text message if they allow you to unlock your phone. That is the first step.
You need to log in to your mi account by your phone, thats binned. When you have logged in via plex vpn wait 72h. to unlock your phone by mi unlock program.