Hi all,
I have just experienced what appears to be this exact same issue.
I’m running 3.6.9 on a Pixhawk 4, and had just figured out how to get the Pixy to communicate with the flight controller successfully (the I2C configuration is a bit different on a Pixhawk 4).
Once I got it working, I took it out to test, and when switching to land mode, I observed the same initial jerkiness that @samucs did. The jerkiness lasts about 2 or 3 seconds, with copter looking out of control and as though it’s going to flip itself (as in samucs video), then the copter begins to descend, but does not land very accurately. You can see it trying to make adjustments but they’re way too small.
I was using PLND_EST_TYPE=0. As suggested above, I will try setting this to 1, and if that doesn’t work, I can try a clean install. But I’d be really interested to figure out what is causing this, as it seems to be an issue multiple people have had.
I had also recently updated the firmware from 3.63 FMUv5 to 3.6.9 Pixhawk 4, so it could definitely be the case that’s it’s something to do with the parameter saving when updating vs a clean install.
I’ll recover a log file and post a video tomorrow, but it looks like it’s the same issue.
Tom