Check that you have turned off budget auto-sync in your Auto Sync settings.  If it is turned on, it will over-write any more recent budgets that you have uploaded. This can be found at the very bottom right of 'Load Data', 'Connections', in the section under 'Budget date range' under the heading 'Auto sync settings'.    Ensure the switch for 'Autosync budget data' is turned to off (no blue is showing).