VB Studio is not allowing to make any changes on few business rules which are created by Helper tool

Summary:

We are working on making some changes on the business rules which were created using helper tool. However, VB studio is behaving very inconsistent and not allowing us to make any changes. i.e. any change we are making on the business rule is immediately reverted back/ or reverted back once we click on another business rule and come back.

For example,

• If we are defaulting a field and entering a value, the field is immediately cleared out (example we tried to default "Use?" field on create requisition page with expression "ORA_POSITION", but the expression is immediately cleared out. The expression is correct and working on other rules)