I have come across this issue too. I tried to figure it out by install jsFormat as follows:
-
Open Package Control panel command+shift+p (mac), install package.
-
Install jsFormat.
-
Edit the shortcut for the jsformat:

-
Choose Key-Binding user, then edit
[ { "keys": [ "command+l" ], "command": "reindent" }, { "keys": [ "ctrl+shift+s" ], "command": "auto_save" }, { "keys": [ "ctrl+alt+f" ], "command": "js_format" } ] -
So next time when you try to format json code, just use ctrl+option+f for mac. Not mac, just use ctrl+alt+f
That’s all.
Hope this will help you.
Cheers