Why wont youtube let me change video resolution?

• youtube app version: 10.08.53


• android version: 4.4.2


• device : Acer A3-A10 10" tablet

My youtube app recently stopped allowing me the ability to change the video resolution.

For example when watching a HD 720p video , if I go into youtube video quality settings the menu shows a list with all quality settings

• Auto


• 144p


• 240p


• 360p


• 480p


• 720p

But if I select a value, the window closes a directs back to the video, but the resolution doesnt change. How can I change the video resolution.