ARCS - "Generate all" action clears data on summary reconciliation

We work with summary profiles. In our mapping there was a mistake where data was going to the summary profile directly. We got some data load errors for this, but it seems that the data ended up there anyway.

Our first problem was that the ending balance dit not appear on the summary profile. We found out that with the "generate all" action, the data was correctly populated in that field. I tried to do this for anonther period and all of a sudden, the data dissapeard from the summary profile.

Can anyone explain what happend? Thank you!