Is firefox hiding from the energy monitor? Since Firefox 38, it is no longer showing in the activity monitor in the energy tab, are other people experiencing this?

How can a process hide from the energy monitor in the first place? I think this can be abused by apps which are trying to hide the fact that they are using lots of energy. 

In the image note that 1) Firefox is running as indicated by the Dock 2) The energy tab should show all apps, not only big energy wasters which it does, except for firefox. 

Crossposting: Mozilla support forum
Nope. For one, Fx 38.0.1 shows up in my Yosemite 10.0.3. 

Energy tab only displays at most 23 items. That could be why.