Cube Black Failsafe problem

When I set Failsafe from Radio to " Enabled Continue with Mission in Auto Mode"
and when I fly in Auto mode, after 900m distance RTL activate. But Why?

Can you share the log?

It is difficult to say anything without a log but maybe you are breaching your circular fence around home? Probably you’re just triggering other failsafe that do not have this option to continue with mission.