trailhead Challenge"Group And Categorize Data"
https://trailhead.salesforce.com/projects/create-reports-and-dashboards-for-sales-and-marketing-managers/steps/group-and-categorize-your-data

I am trying to get through this project but for some reason keep getting this error on the first challenge:
Challenge Not yet complete... here's what's wrong: 
The 'Users Not Logged in Last 7 Days' report does not seem to grouped on 'Close Date' by Calendar Month.

This makes no sense to me because its talking about two different reports.....I have tried redoing the first three parts of this projects recreating the reports and still get this error.  

Here are the requirements from the previous sections creating the reports its referencing:
Users Not Logged in Last 7 Days (no grouping on Close Date by Calendar Month)
Customize the standard Users Logged in This Week report to display users who have not logged in during the last seven days:
Click the Reports tab.
Under All Folders and select the Admin Lightning Experience Reports folder.
Click Users Logged in This Week LEX.
Click Edit.
In the Filters pane, from the Range picklist, select All Time.
In the Filters pane, click Add.
Create the filter:
Field Field OperatorValueLast LoginNot equalLast 7 Days
Click OK.
Save the report as a new report called Users Not Logged in Last 7 Days in the Adoption Reports folder:
Click Save As, and then complete the Save Report details:
Report Name: Users Not Logged in Last 7 Days
Report Description: Who hasn’t logged in the last 7 days?
Report Folder: Adoption Reports
Click Save and Run Report.

Opportunities by Rep and Close Month​ (THIS is the report that groups on Close Date by Calendar Month)

Next, we’ll modify the Opportunities by Rep report to group by the calendar month of the Close Date:
Click the Reports tab.
Click All Folders.
Click Global Sales Reports.
Click  next to Opportunities by Rep, and select Edit.
Drag the Close Date column heading into Drop a field here to create a grouping drop zone.
Click in the Close Date summary row, hover over Group Dates By, and then select Calendar Month.
Change the format of the report to matrix:
Click Summary Format and select Matrix.
Click Show, and then click Details to deselect it.
Save the report as a new report called Opportunities by Rep and Close Month in the Global Sales Reports folder:
Click Save As, and then complete the Save Report details:
Report Name: Opportunities by Rep and Close Month
Report Description: What opportunities do your sales reps have in the pipeline and when do they close?
Report Folder: Global Sales Reports
Click Save and Run Report. 

I tried to change the name of ther Report but then it is giving me following error