I'm stuck on step #2 of Einstein Analytics and Discovery Insights Specialist superbadge.  I'm getting this warning while checking the challenge:

The step "Churn Tenure' is in compact form, so the filter values need to be specifed as a minimum and maximum
The static step that feeds has the following the value:
 

"Tenure_Length": {
                "broadcastFacet": false,
                "label": "Tenure Length",
                "selectMode": "single",
                "type": "staticflex",
                "values": [
                    {
                        "display": "High Risk",
                        "value": "1 to 12 months",
                        "min": 1,
                        "max": 12
                    },
                    ...
                ]
            }

I'm using selection binding for min and max values.  The dashboard is correctly filtering:


Any ideas? 
I've tried a non-compact form step where I inject a saql fragment into the query, as well as where I inject min/max values using a range filter serialization...All these efforts end in the same challenge failure message.

Any help/suggesitions are welcome!

Today my Lightning sandbox is having some serious behavious issues. 
I run into following errors:

• Unfortunately, there was a problem. Please try again. If the problem continues, get in touch with your administrator with the error ID shown here and any other related details. An internal server error has occurred Error ID: 1986783592-9485 (1990134024)
• Uncaught TypeError: Cannot read property 'b' of null throws at https://cs88.lightning.force.com/auraFW/javascript/ywi4clSWfDw6pOdt8rkxkQ/aura_prod.js:268:162

When I refresh the window, the error disappears and I can continue working untill the next one appears, and so on.

Anyone have any clue what is happening?