At one point my son thought the dimming on the switch was done via pressing quickly/repeatedly rather than just press and hold…so maybe someone in your family hit the magic combo of presses when trying to dim the light and then giving up and hitting off.
But good news to have it fixed, I’m sure. 
The physical switch itself.
Haven’t gotten it to work, but will try again.
it took me a couple tries to get it, the ‘press on three times’ has to be done pretty quick!
I had one GE switch do this. Jasco replaced it under warranty. They sent a Plus in it’s place not that I needed a Plus version.
Updating… After a LOT of searching, and while using only the ‘new’ Samsung Smartthings app, here’s how to control the blue LED on a GE zwave+ paddle switch, model 14291.
First off, make sure the light even works. After adding it to the hub, check to see if the light comes on at all. If it does not come on in the ON or OFF position, press the top paddle SUPER fast 3 times, then the bottom paddle once, in very quick succession, all 4 strokes.
Verify the light comes on in either position.
Now, the options.
Go to your smartthings webpage, (NOT the app) and go to devices tab, and click the device, IE, Light switch-whatever-you-named-it.
Above Preferences, it should say Current States. Check that there is an entry titled IndicatorStatus, should say when on or when off. This is when the led light will be ON.
scroll down to -Preferences-, and it should say (edit) beside that. Beyond that, to the right, it should say enum and then Value. Again, this is what status the switch is turned to when the LED is ON.
Click edit.
The page changes, and you’ll see:
LED Indicator - Turn LED indicator… (here, in this box, simply enter on or off. no caps, etc.
(Off=LED off when switch is ON, LED ON when switch is OFF. ** On=LED on when switch is ON)
Then hit Save.
Go back to the devices page, give it a minute to refresh, and it should be accurate, as well as the LED turning on when you want it. These are the only 2 statuses (LED on or off) that I messed with, and after piecing together several pages on info.
Hope this helps someone with this switch, the 14291, and it’s possible it works with others, YMMV.
Similar issue adding several GE / Jasco zwave outlets (TamperProof) all but one added with correct state on light. Careful read of the instructions, included in the box, in the bottom right of step/box #3 says “quickly press the ON/OFF button 10 times, the light will invert if done correctly” … i did this and it returned to the desired state (ie light on when power on)