Single select field options from API

[LaurynV]

Hello! I'm having trouble allowing our AirTable users to add a new option to a single-select field. Also, any changes that happen to that field break an interface where that field is included both in a grid and also as a filter option. The field is only letting me add new options -- I am the one who created the field/changed up the format of how it was. Not sure why that's happening, please let me know if you have any ideas on how fix it.