May be said before ...
After making a second adjustment, "reset to adjustment defaults" button reset to previous adjustments made by the user, not to default values ... is it an expected behaviour?
And, secondly, only preview is resetting, sliders do not reset to previous adjustment made by the user ...
What is the name of that slider thing ... when your mouse is on the slider name, there appears a two sided arrow for adjusting the slider?
All the adjustment layers have this thing except color balance ... I can not reset the sliders on this adjustment panel by double clicking on the slider name.
Are you using photoshop cc (photoshop version 14)?
(there is a known glitch in adjustments layers in photoshop cc of the sliders not resetting themselves)
What operating system?
I don't know why the color balance adjustment layer is different in the respect to being able to double click on the names to reset the sliders.
It does seem odd.
Those two sided arrow things are called Scrubby Sliders and you can get them in the color balance adjustment layer by hovering over the input box or the right side
while pressing Crtl key.