We're having trouble with the "Extending Reports using the AppExchange" module in Trailhead

We keep getting the same error when checking the challenge at the end of the module:

Challenge not yet complete... here's what's wrong: 
The 'LEAD Trend by Source' dashboard component does not have the wedges set to 'Lead Source'.

Wedges ARE set to 'Lead Source', did anybody get this error message? do you know what the solution may be? Thank you!