I postet maximum length of char sets.
See double sized specific language letters.
#Text length 16 chars
balmy flare
errant rapids
Dear Traveler,
Regarding the issue you reported about the nickname change, it has been confirmed that in the nickname settings, only "ascii" characters and numbers are counted as one length unit each. However, for characters in other languages or some special characters, the system will consider each character as two length units to calculate.
We understand that this may cause inconvenience to you.If you have any other questions or need further assistance, please feel free to contact us.
Wish you a pleasant gaming experience!
balmy flare
Maybe regional collations on Server to prevent double sized character.