Use buttons combination Volume+ & Volume- & Power-Button to boot to TWRP. Other methods don't work anymore with HM3/ido. It changed since weekly 7.3.9.
1. Turn off your phone
2. Press & hold "Volume+" & "Volume-" & "Power Button"
3. When mi logo show up, release"Power Button" but don't release "Volume+" & "Volume-" until twrp appears