My remote version does not support that feature. Until the update, when I turned on the Roku, the TV also powered on. It no longer does and I have to manually turn the TV on. No big deal, but I think the update broke this.
Ah. CEC can be weird. Could have been an update/change on the TV side. Perhaps it is powering off now rather than a stand-by mode which is usually needed for HDMI activity to wake it. I don't and haven't owned a Visio though. You could just plunk down for an enhanced remote and not worry about it again - they're not terribly expensive. I finally did a couple years ago and wondered afterwards why I hadn't sooner.
Being in IT as well, I completely agree. Thanks for letting me know that I am not the only one. The feature continues to work fine on my Samsung. This leads me to believe it is a brand specific issue of some sort.