Reports of total contracts by month


I’m trying to make a report that will show me the total of contracts by month of date reminder.
Which means for every month, I want to know :
this month I have a reminder to invoice this company and this company, which means a total of xxx euros to invoice.
And this for every month of the year.

For now, I’m tryng with groupings, and my reminders always start the first day of months, so here’s what I did (first screenshot - I don’t know how i can upload screenshots, I’m going to do my best).

The result is almost ok but for some reason, some records are duplicated.
As you can see if I’m able to upload screenshots, it’s ok for month of january to april :

Then in june, I have some records duplicated :

I don’t understand why and I don’t know what to do.

Could someone please help me achive this ?
Thanks a lot.

anyone willing to help me ?
I think there’s a bug with reports, when choose grouping options.

still having the same issue, I’m struggling with reports.
Is there a documentation somewhere where I could find more information than in the online help ?
Or anyone willing to help me ?
It’s really important for me to have these reports.

If the standard report module is not enough you can try the report tool created by Marnus van Niekerk where you an create your own queries. Check his post here: