Cell Formatting Changing

I am putting together a billing spreadsheet for work, and I have applied a custom cell format for the "Job Number" column that should format cells "0000-000". I applied it and moved on, but when I tried to sort by job number it did not arrange them in the correct order. So, I checked the cell formatting and it had been changed to Portuguese zip code. I changed it back and re-applied the custom format, and it automatically changed back to Portuguese zip code. For some reason, this formatting interferes with my ability to sort the sheet by Job Number. Why is it changing my applied format to a Portuguese Zip Code format, and how do I make it stop?

Just a guess, but if it is a table, maybe changing the top cells solve it.

Thanks for the welcome and the help!

Our job numbers are the year and then the job number so "2022-383" or "2023-497" etc. When I attempt to sort smallest to largest, for some reason, some of the 2022 jobs still mix in towards the bottom with the 2023, etc. I'm not sure why the zip code format would cause that, but your work around seems to have fixed it. It is sorting correctly when I use that.