Why can't I enable the system UI tuner?

[AC Question]

Can't enable system UI tuner

I have an HTC one A9. And when i try to enable the system UI tuner by holding in the settings gear button it never starts spinning. when i go in to the software information it says that i have the android version 6.0, and it doesn't say that i have any update to 6.0.1.

 

[Javier P]

Re: Can't enable system UI tuner

HTC didn't include the UI tuner in the update. Sorry.

 

[Stovall2016]

Re: Can't enable system UI tuner

HTC didn't include the UI tuner in the update. Sorry.

what about the T-Mobile LG STYLO?