Unexplained change in monthly budget allocation

I created a folder for a reoccurring expense that will only occur once per year. Let’s say it is $132.50. Note: I have elected to run primary monthly budgets. Correctly so, my Budget Allocation Report displays as $11.04 per month. (132.50/12= 11.04). However, as soon as I assign a date when the expense becomes due, I note in the MONTHLY expense in Budget Allocation Report changes to $132.50/month which appears to be incorrect. Am I missing something or doing something wrong, or is the software calculating this incorrectly?

When is the date? If it within a month from today, and you have not added anything to the envelope yet, GB will calculate the amount you have to put in this month to fill the envelope. Once you pass the due date you will have 12 months until the next due date, so the monthly fill amount will appear as you expect .