Innovation & Ratio Flat-lining (external vision mode SLAM)

I use the EKF2 and external vision fusion in a SITL configuration.

While I fly, the drone behaves strangely at 4min25sec of the log the innovation and test_ratio goes flat-lining. I can’t figure out why the position sends from the companion board is still there and it does seem to reject the position, but the estimate is not that far from the vision pose…

Here’s the link of the log :