Alert Composer using custom DFF in Expression

Summary:

Flexfield is not showing in the Expression → Attribute in Alert Composer.

Created 2 flexfields.

WSBC_CLASS_SHORT_NAME was created few weeks ago, WSBC_OFFERING_NOTIFICATION was created yesterday.

Both fields properly shows on the Learning > Offering page.

Trying to setup Alert Composer using the flexfield WSBC_OFFERING_NOTIFICATION.

Under Alert Composer WLF_00010 → Add Filter

Choose Resource "learnerLearningRecords/selectedCourseOfferings/offeringDFF" > Edit

Under Attribute, pick "learnerLearningRecords/selectedCourseOfferings/offeringDFF".

I see wsbcClassShortName appears, but no wsbcOfferingNotification.

For testing, I ran REST API for the resource, and I was able to get the result on both flexfield.

The only difference between two flexfields is, wsbcClassShortName was created a few weeks ago, and wsbcOfferingNotification was created yesterday.