I had tried several different ones and after a period of time, the widget would stop updating or responding to the manual update input from touching the widget.
IMHO, this should be addressed by Samsung and carriers ASAP.
Since a couple of days/weeks, I noticed that my widgets aren't updating anymore on my home screens of my Nexus 6 (Android 6.0.1).
It's not related to a single widget, it's all of them.
The only thing that seemed to work was restarting the phone.
Well, I knew there had to be some type of culprit to blame for this behavior.