Numbers Automatically Reformatting Cells

Can you provide an example? The only examples I can think of offhand are when data is entered into an "automatic" formatted cell and Numbers assigns what it thinks the format should be (while still calling it "automatic"). But after deleting the cell contents it can be changed to another format.

What Barry was saying is accurate. Here is an example:

1. Format cell B2 as number with 2 decimal places
2. Enter a number into the cell and it gets formatted with 2 decimal places as you requested
3. Enter a date (such as 8/26/22) into the cell instead and the format changes to date&time because the data you entered does not match the format you chose. Numbers recognizes it as a date&time.
4. Enter a number into the cell and your chosen format comes back, with the two decimal places.

If memory serves, this happens only when a value entered in the cell cannot be expressed using the format assigned to that cell by the user.

Regards,

Barry

This answer is incomplete. It needs to tell user how to assign the cell or column of cells his/her desired format.

New Numbers users migrating from Excel need more detail. (MS requires a separate iOS subscription even tho users have a standalone copy of current Office suite.)