Big arabic permalinks not work

It depends on what encoding you are using. If you look at the database structure of wp_posts, you will see that post_name field is varchar(200)

So, at most it can store 200 bytes of data. If you are using UTF-16 encoding, it needs 4 bytes to store an Arabic character. So, at most it can store 50 Arabic characters.

For different encoding, it will be different. See