Localization problem: GPS drift when using visual odomery and INS

So, I have been configuring around robot_localization package to use GPS and IMU together with visual odometry from rtabmap, but have weird behavior. To begin with, I use Orbbec Astra as source of visual odometry, which is then sent to first and second instances of ekf_localization node, which produces visual odometry+imu as first instance and visual+imu+navsat odometry from second. As well I have navsat_transform node which takes output from second ekf instance, which is odom_gps and gps/imu data. Then i use launch file from rtabmap_ros package called sensor_fusion, where I removed the robot_localization node part, because I want to use configuration described above. First instance works fine, visual odometry also seem to be reasonably stable, however second instance and navsat_transform node output unstable behavior. At the start the position is around ~20cm a drift in x and y and if some small slow movement is done with the base, it starts drifting around to positive and negative directions (sometimes to one, sometimes to both). I tried to do this outside in more open space to give GPS to catch reasonable amount of satellites and the problem still persists. I have read one similar question before, but his problem was that he used wrong output - from first ekf instance. I double checked if I had that and I am sure i use output from second ekf instance. I would really appreciate if anyone had similar problem and managed to overcome it. I post the launch file of both rtab and robot localization (https://www.dropbox.com/sh/57zaiqweulrxslf/AAB3DxMIABsECWNLPr1P7H4ia?dl=0) as well image of drift. Also geared used is: Xsens MTi-G-700, Orbbec Astra. **Robot_localization.launch** [true, true, false, false, false, false, true, true, false, false, false, false, false, false, false][false, false, false, false, false, true, false, false, false, false, false, true, false, false, false][false, false, false, false, false, false, true, true, true, false, false, false, false, false, false][true, true, false, false, false, false, false, false, false, false, false, false, false, false, false][false, false, false, false, false, true, false, false, false, false, false, true, false, false, false] **Sensor_fusion.launch (from rtabmap_ros)**