Accumulated depreciation on fixed asset not totalling correctly. NBV incorrect as a result

We have a fixed asset that has had its original cost changed on the FAM record.

As a result the cumulative depreciation is only aggregating the depreciation record since the original cost changed.

Scenario:
Fixed asset acquisition was Aug 2018 (18m ago).
Asset original cost changed start of Jan 2019 (11m)
Cumulative depreciation on the FAM record only accumulates the depreciation since Jan 2019 (11 depreciation entries have been run)

Depreciation calculation each month is correct (i.e is the new original cost depreciated straight-line over its life).

How can I get the cumulative depreciation to accumulate depreciation since Aug 2018?

Thanks in advance!