Estimation backlog and detail view not in sync

[tjhkuijpers]

Instead of using the default User Story field for estimates, I am using a custom number field which gets it value via a call to the CustomField's updateValue(...). This value is correct when shown in the detailed view in the backlog (both as Estimate field as well as selecting the field to show in the general section of this view). The value in the backlog (in the ellipsis) is not shown until I perform a reindex of the issues.

Why is the value in the backlog not updated and how can I achieve to get the correct result shown there?