@Raphie ***
i'm not an Immigration officer in Thailand, neither is anyone else in this group I assume.
Buuut, I would bet that it doesn't present a problem because it is still your passport number just with the added 'checksum' (a technical term you don't need to be concerned about).
Especially since it was issued by the Thai Embassy and they should know what they do. If you are overly worried just ask them again. ๐