Double Crash and no explanation

Any help with this would be greatly appreciated. I reviewed the logs for these quadcopter flights and am clueless. The first crash could be because of bad GPS, however, the way the quad acted was very erratic. The second crash everything was perfect then it just randomly lost control.

The issue is the desired roll and desired pitch for both cases were in line, vibrations were no issue, GPS on the second crash was excellent, and I can’t seem to find the issue. The only red flag on the first crash was the EKF Horizontal Variance was maxed out, however, the compass was not showing any errors.

Any help would be greatly appreciated! Very strange crash on two separate quads in similar configuration.

Here’s the Logs and the .tlog of the first flight. the .tlog of the second flight did not save for some reason.

dropbox.com/sh/7cad1ph5njhx … mLDia?dl=0

Thank you

I’m no expert but, Your tlog shows very high Z vibrations.
Do you have dataflash log for same flight?