Text to speech for Cantonese

When doing the Cantonese course/lessons on my phone (Samsung), I am constantly getting a pop up which says “This language is not supported by your active TTS engine”. This is getting a little annoying in itself, but moreover, the message pops up over the buttons for me to click whether I know a word or not.

I am currently using the Google text to speech option - and I have it set to Cantonese. I have also tried using the Samsung text to speech option, but it makes no difference. The text to speech actually works - it is just this annoying pop up which wrongly tells me it is not working.

Is there a way to switch this message off?

Thanks for reporting the issue, we will look into it.