Copter 3.5.0 rc4 altitude problem

Hello everyone
Today, I use the Quad with Pixhawk and Here+ RTK, in the flight i found a altitude of drift is very serious, so I switch to RTL mode after the plane appears to be a normal landing, but the height shown in the MP is constantly mutated, the log upload, I guess it should be firmware (ArduCopter3.5rc4) BUG, need help analyze this problem.

Copter_Here (2.9 MB)

Seems like similar to that I reported here: Altitude issue using SF11/C Lidar

In my case I noticed the shift evidently somehow relates to in-flight switches between EKF’s.

Thank you for your reply!