Customized resrc does not save fields when rescheduled bookning

Hi

has anyone done customization to resrc9.ntf and added new fields?

We have added some fields to resrc9.ntf and new values in these fields does not get updated when we do a reschedule.
If I make a new reservaton - works fine.
If I change the customized field and save - works fine
But , if I change the reservation a n d the customized field - the old valued is not changed.

It is the same result with the resrc8 - with the Notes8.5.3 client or the Notes9 client .
Domino is on 9.0.x

//Christina