Create Accounting for FA picks up data for 1 old period. Why?

Oracle EBS 12.1.3

Assets

Create Accounting was run for Jun-20 period and depreciation data was picked up for that period as expected.

But also lots of data from Feb-19 period was picked up and failed to account as the period is closed.

This data was not picked before and so has suddenly become unaccounted.

Can you tell us why ?

In XLA EVENTS I can see many events unaccounted with a creation date 20-MAR-19 (When Depreciation was originally run for FEB-19 period) but event last update was 09-JUL-20.

select distinct event_date, event_status_code, process_status_code, count (*)

from xla_events