Operator "Within the next n full month" not working

When we make a report able to be filtered, and the ‘within the next n full month’ operator is selected, any values typed into the from or to dates do not stick. Is this a known bug?

I can’t reproduce the error.
Can you post some pictures of your report settings: select, manipulate and present?
Which KReporter version is it?
On which CRM in which version?

Select:

Manipulate:

Present:

Kreporter 4.2
SuiteCRM 7.8.17

Selected operator in your report in YTD. Current year until today.
That’s not within last n full months.
I see you have a custom SQL function on invoice date.
Does last n full months work when you remove it?