Unable to update Default Distribution Account

Hello,

In Invoice Lines, we select Default Distribution Account. Once this is entered & the Invoice is validated, the Default Distribution Account is greyed out. However, Invoice Distribution is editable.

If we make account changes (after Invoice Validation and before Create Accounting is run) using the Distribution window, Default Distribution Account (in Lines) is still showing old ccid. We are unable to edit this field. Is this intended function?

Thanks,

Siva