Compile value set hierarchies - not updating Code Combinations

We are using R12.1.13.

We have an issue where users are making change to Segment Values in the Accounting Flexfield.

Sometimes users will e.g. update the settings for Account Segment - e.g. remove Enabled tick:

And set the qualifiers like this:

When they save the changes, the system spawns the "Compile value set hierarchies" job to run.

I would then expect that job to update any Code Combinations which include that Segment, to e.g. be end-dated, and to not allow posting and budgeting.

However, that's not happening. The Last Update date on the Code Combinations is years before the change was made to the individual Segment.