I verified that the Budget setting is set to all categories and I quit the Frugal month of August and then recreated it leaving all categories and all accounts selected. The spent this month and the spent values for the frugal month are still different.

James Bexten they should be the same assuming, like you said, you selected the exact same categories for that frugal month as the ones in the currently selected category view on the Budget Tab. This is an area that's easy to mess up unfortunately and in the future I think I'd like Frugal Months to just use Category Views like all the other features. One thing to note is is that the Budget Tab does not allow filtering of accounts, so if you did any sort of account filtering on the Frugal Month creation, there's a good chance that's the reason (assuming the account you filtered out is one that you spend from).

If none of that helps and you do believe it's a bug, I might need your help in identifying the issue (which may involve emailing support@lumyforynab.app). One other datapoint to check is the income v expense report--do the expenses (assuming same accounts/categories) match either of the futures shown on the Budget tab (Spent this month and Frugal Month Spent)?