I tried flashing an (I) flyme on a chinese phone (A) using https://forum.meizufans.eu/topic/2599/guide-how-to-install-i-international-firmware-on-your-chinese-mainland-meizu
by copying the update.zip to the root directory. Flashed fine but stuck on bootloop. I tried using recovery (copying a good firmware to recovery directory via PC) but I have a suspicion that that the phone is accessing the old file on root directory. No Idea what to do.