How will this effect table of figures/tables, where you are able to click on the list to take you directly to the corresponding figure/table?
Also, that means that the numbering will be consecutive, rather than Table 1, Table 2, Figure 1, Figure 2...etc.

Assuming that you haven't saved and closed the document, you can use Undo (Ctrl+Z), possibly repeatedly, to "restore" lost captions. In the future, remember to not select an existing caption before opening the Caption dialog box.

To update a table of figures or table of tables: Click in the table, press F9; if prompted, choose to update the whole table.

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Stefan Blom
Microsoft Word MVP

Microsoft 365 apps for business
Windows 11 Professional