A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
Select one of the cells that displays the error flag. Then press Command-1 and observe the format for the cell. I suspect the cell is not formatted as Zip Code as you thought it was.
I tried to reproduce the problem in version 16.19, but the problem does not reproduce.
If you want to try version 16.18, the next general release, you can get it today by joining Insider Slow. Or you can simply wait till next week when 16.18 is distributed to everyone.