@johndoe answer did work for me.
Let me give the step by steps as on this date.
go to alexa developer console -> skills tab
https://developer.amazon.com/alexa/console/ask
see what is the language of your skill.
mine is english / United States
Now go to alexa app on your phone
click on more in the bottom bar of the app.
click on settings -> alexa app settings -> change language to the one in your developer console.
now again click on more in bottom bar settings -> device settings -> select device -> click on gear icon in top right side -> change language to the one in your developer console.
now it should work.
if it doesnt work -change language in your phone settings , restart alexa app , restart alexa device.
now it should most likely work.
Feel free to HMU.
cheers.