No, Facebook should not be spending any budget from inactive campaigns. If you’ve duplicated your campaign and turned the original ones off, only the active campaign should be using the set daily budget.
What you’re seeing is likely due to a reporting delay, a misinterpretation of the data (such as looking at lifetime spend), or the previous campaigns being turned off after some spend was already allocated for the day.
Make sure you’re checking the reporting with a custom date range (e.g., "Today" or "Last 7 Days") and confirm that all levels—campaign, ad set, and ad—of the older campaigns are completely toggled off.
While the daily budget setting remains visible on paused campaigns, it won’t be used unless the campaign is active. So you don’t need to remove the budget from inactive campaigns—they won’t spend unless you turn them back on.