Pretty sure someone is trolling and changing the root flag.
Can someone provide the root flag to me if I give them the administrator hash?
HTB uses dynamic flags. There is a new flag every time the box resets and different flags on each VPN connection.
If rooted the box and gave you the flag, it would be no use to you and we would probably both get banned for violating HTB’s rules.
When you get a flag you need to use it fairly quickly.