The reason those "Reminders" are not showing up is because of the filter when you are creating your report.
When you click into Note Reports and are setting the criteria for your report, be sure to click the "Created From" filed as opposed to the "Note From", which is the default. The reason those Reminders are not showing up is because this report is only showing notes that are "for" the specific dates you are entering. If the reminders are outside that date then they will not show up for a report of "today's" notes. For example:I have attached a pic below that shows you that filter, as well.