I have an Redmi 3 pro with unlocked BL and the latest "official" weekly 7.3.9 from xiaomi.eu and latest TWRP 188.8.131.52 from official twrp site.
I am unable to flash twrp.
I flash it with fastboot flash recovery recovery.img then boot into it using fastboot boot recovery.img with no issue at all.
if i reboot into recovery from twrp itself it still works.
if i let it boot the phone in its bootloader (POW+VOL_UP the one where you can choose "download" "fasboot" or "recovery") and i select recovery, it does not boot. The phone boots instead.
if i choose from the updater to reboot in recovery, same.
if i choose from flashify (which shows me "stock recovery" is installed), same.
if i use adb reboot recovery same.
i can only boot it using command fastboot boot recovery.img.
It just looks like the twrp flash says OKAY but it's not being flashed.
I've also tried cofface recovery with no success.
i've also tried official twrp app with no success.
everytime flash goes fine and successfully, but i'm unable to boot the phone in recovery itself.
i must always use fastboot boot recovery.img