Create a system module with time scale - "year" and keep Time Dimension in page panel and publish page selector to the Dashboard.
In your module create one line item Month set as boolean format and write formula as TRUE then create saved view with month filter and publish to the dashboard and sync with Time in the Edit Dashboard. please see the below screenshot
Let me ask you a crazy question, is the first month of your fiscal year May? If so, the reason it is defaulting to May, June, and July is those are the first months of the first quarter of the initial year. To get around this, while not elegant, is to have the user specify the year in a previous dashboard, thus the above dashboard is not the the first one seen and then the system will respect the year chosen and will render all of the months.
Thanks for the help. Fiscal year starts from Nov and is it possibly because somewhere in the app, quarter 3 is selected as default and the dashboard shows 'FY 19' selected but it is not really used unless we select it again?
When you published the dashboard element or view, did you publish it with the filter already "on" and if so, was there a formula on the filter? For example, when you publish the view, the filter should be on, pointing to the SYS Time Filters module for all months. But, the formula for that line item should be TRUE (so no logic, just true). After it has been published, go back to the SYS Time Filters module and replace the TRUE with the actual logic.