Hi reading-card,
I can't reproduce this here.
I took a plane and made it editable.
Use Fields - checked.
I placed a Sphere field in the list.
Unchecked the Filed option.
Deleted the Sphere Field (not needed)
The values stay the same.
Since you mentioned Deformed and Non-Deformed.
I can't tell you anything else without a Project file (reduced to the problem); only check with tech support.
All the best