Odkmeta warning message "The following fields appear in the form but not the data:"

1. What is the problem? Be very detailed.
Hello Everyone,

I am getting the following warnings when running my import.do file: "The following fields appear in the form but not the data:" and "The following fields appear in the data but not the form:".
Both survey.csv and choices.csv are labeled appropriately (e.g., survey contains type, name, label and choices contains list_name, name, label).
Any help in figuring this out is highly appreciated!

2. What app or server are you using and on what device and operating system? Include version numbers.
using ODK Aggregate and ODK Briefcase - v1.16.0 and stata 15.

3. What you have you tried to fix the problem?
Lots. Googling these messages yields nothing helpful. Checked and double-checked for any errant alphanumeric values in the choices sheet.

4. What steps can we take to reproduce the problem?

5. Anything else we should know or have? If you have a test form or screenshots or logs, attach below.

THANKS!!