I have several different screens where I am attempting to utilize the webcomponents smart grid.  Everything works great except when I specify headers with Sort, Filter, Conditional Formatting, Customize Columns.  Search and Group always work, whereas these others will work randomly, if they work at all.  I’ve removed all of our custom code, dependencies, etc, and have gone as far as to drop our api call into the “Grouping Header Panel”  demo.  Same result.  The only thing I can come up with that is common to all of the screens is that they are getting JSON from an API call.  I’ve tried everything I can think of.
The page I am currently working on has Filter, Sort, Group and Search.  Group and Search work, Sort spews the following error each time it is clicked:
Uncaught TypeError: Cannot read property ‘$’ of null
at HTMLElement.value (smart.grid.js:8)
at HTMLElement.n (smart.grid.js:8)
at n (smart.grid.js:8)
at HTMLElement.value (smart.grid.js:8)
at HTMLElement.value (smart.grid.js:8)
at HTMLDivElement.<anonymous> (smart.grid.js:8)
at e.value (smart.grid.js:8)
Clicking on Filter does nothing, as if no event is even registered.  Interestingly enough, Sort, Filter, and Group all work in the column headers.
Chrome thinks all of the js and css files have loaded, but the behavior I am seeing suggests otherwise.  Am I missing something or are others experiencing this issue?