https://drafts.csswg.org/css-text-3/#word-break-property

แและ·ตัวอย่าง·การเขียน·ภาษาไทย has two many แ characters at the start.

Also, are we sure about the word segmentation for these examples? I tested it by using Firefox to wrap the text, and ended up with the following words:

และ•ตัวอย่าง•การ•เขียน•ภาษา•ไทย

Literally, that means "and sample how write language thai". The current spec word divisions seem to map rather to that of the translation(?)