Problem with EKF position estimation


I’ve entered some strange issues with my copter with flying in offboard mode. Sometimes it flies away not taking into account velocity setpoints from my program. During log analysis I found that local position is calculated wrongly, the data from my accurate gps(its rtk) is somehow ignored. What can cause it? And could you advice me a proper way to analyze EKF working process? I found parameters EST*, but I couldnt find their descriptions.

Here is image with GPOS_Lat vs TIME_StartTime (red continues line) and GPS_Lat vs TIME_StartTime (dashed line)

Thank you in advance,

Hi. i have the same problem. pls, let me now if u can fix it =)