Rate requirement change from variable rate age bands to standard rate but with age bands calcs once

Summary

This one is puzzling to me. Rate requirement changed from variable rate age bands to an age band rate where the rate never changes once the employee makes election.

Content

Looking for guidance.

I'm not even sure if this can be programmed or not.  But the benefit admin said the vendor for critical illness said their policy reads the original rate that was calculated based on the age of the employee for the life event, can not change.  Currently it is set up like an optional life plan were the variable rate is tied to age bands.  The rate gets recalculated when life events are processed.  Has anyone set up a plan where the rate starts out being based on an age but then doesn't change?