Apples Thai keyboard Issues
Apple’s Thai Keyboard Problem
The Dictation function is not working properly on Aplples iOS. If you have the Thai keyboard on your Apple device. Go to your email messages. Create a new message and go to the third second or third line in the message box and try using dictation to create a message.
It Works fine in the fist line and in the address box But does not work at all from the second line down in the message box. This also occurs when using dictation in third-party apps. 
I have been speaking to Apple about the issue for four months and they acknowledge there is a problem but they still have not resolved the issue.
iPad, iOS 9