Extenstion of Planning Area Time Series interval deleted data from planning books

Hello,

When created plannig area time series in /sapapo/msdp_admin , some key figures (manually uploaded data) has disappeared from the planning books.

original date was. 01.01.2019 - 31.01.2023 , and the modified was 01.12.2021 - 31.12.2023.

Is it the standard way that date disappeared? What is the root cause?

Any ways to avoid such except backing up the Parea?

Thanks

Br

Geri