Some characters are removed when editting permanent link.
Example "สวัสดีครับ" to "สวสดครบ"
problem found on Wordpress version 6.4.1
Please help.
Note: I tested on Wordpress version 4.5 it work fine.
Wordpress 5.0+ A new editing experience for WordPress is in the works, code name Gutenberg, Gutenberg is the WordPress default editor, replacing the previous classic editor. it has a bug with thai permanent link.
I fixed it by installed Classic Editor Plugin maintained by the WordPress team that restores the previous ("classic") WordPress editor and the "Edit Post" screen