EKF2 Yaw estimation error


I am trying to send motion capture data to a pixfalcon running px4 autopilot version 1.8.2. The motion capture system (mocap optitrack) is being published to the topic /mavros/vision_pose/pose. I am currently using EKF2 to estimate the position of the drone, I have set EKF2_AID_MASK to 24 (yaw + vision fusion). The barometer is disabled as well as the magnetometer and gps.

When visualizing the data in RVIZ, I am able to see both the mavros/vision_pose/pose and mavros/local_position/pose topics, however, the local_position topic keeps on yawing while the drone is still. When the drone is being moved around, both the local_position and the vision_pose move but the local_pose is constantly yawing so they are never in line.

I have tried upgrading the px4 firmware to 1.9.2 but this did not solve the problem. The sensors were re-calibrated multiple times and that did not help either.

Here is the log https://review.px4.io/plot_app?log=adaed32e-f5ed-4b1a-853c-c3428d2f0557
link to download: https://drive.google.com/open?id=1USWVzA0lBS1CuPEWLN3ayvZmMS5QhWbd

Any help or guidance would be appreciated, thank you in advance!