How do I prevent S Planner from deleting events on Samsung J3?

[AC Question]

S Planner automatically deletes past events from more than a two weeks before.

This calendar is synced with my outlook calendar. None of the events disappear on Outlook.

Can someone explain why is this happening? Can I prevent this? I would like to be able to see my past events. I don't see in S Planner settings any option to keep the events.

Please help.