Incomplete root on G

Hi everyone,
I have some weird root on my Meizu Pro 5 with G. Root permissions are on in the Settings/Fingerprint and Security/Root Permission/ . I have a list of apps with Allow permission, including SuperSU, BusyBox and Terminal Emulator. When I launch any of these apps for the first time I get a prompt for permission and I choose Allow.
However, Root checker does not recognize the root and Kingroot failed to root the device. When I boot device into fastboot to unlock the bootloader to install TWRP, I see “Fastboot [locked, rooted]” message. Whenever I try to use “su” command in the Terminal it returns access denied or something similar. SuperSU app fails to update the binary, although, ES Explorer has root access to explore files.
I tried to Reset to factory settings - same issue
Tried to flash - firmware corrupt and does nothing.
Not sure when and what went wrong, since I updated to via terminal commands, hence su access.
Do you have any ideas?

After trying different ways around, I figured out the reason for this issue. The problem was that I had a Chinese version of the phone, which could only accept Chinese firmwares. I bypassed this following one of the tutorials, which I am sure every Meizu user came across with at least once. That instruction proposed to install international firmware using either ADB or Terminal commands and by creating an img file out of the original zip file (I cannot post a link here to the article). That instruction offered a 1 time solution for installing an international firmware without actually changing the ID of the phone.
For some reason, which is still unknown to me, the root access got limited and I found myself in the spot, where I could not get an update or proper root access to follow that instruction again.
After several desperate attempts to reset device to factory settings and installing a proper root, I ended up trying to install an old Chinese firmware - it went smoothly, which confirmed to me that I had a Chinese version. I installed all the root and supersu attributes on the phone and then followed the instruction of changing the ID.
After that I was able to flash international firmware straight from the File Explorer of the Flyme.
This whole description is meant for those, who face with the same or similar situation and get desperate in looking for any information on the internet as I did. There is very little help and support from Meizu community be it meizufans forum, xda, Russian 4pda or what ever else. I posted in several of those and no one replied to the issue. So I hope this information could be of any help to those, who get into this situation.

I have the same issue, but I changed the ID of my device to international right from the start. But alas, after installing my SuperSU cannot update binary and gain root management rights. Are you saying that I should flash again, change the identifier again (will it change to chinese one while it is already international?), flash and upgrade to and everything will work?

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