Hi Shawn,
You are right about what most likely occurred. Unfortunately, the field length is not alterable once published. What you can do instead (using ArcGIS Online or ArcGIS Pro):
1) Add a column to temporarily store the existing answers
2) Calculate the values in the existing choice column to the temporary column
3) Delete the existing field
4) Add a new field with the same name
5) Calculate back the existing values from the temporary column to the new column
6) Delete the temporary column