Crashed in autotune twice

Hello everyone,
Crashed my hexa copter twice within 24 hours.
Day one: Ver.3.3.2 autotune = all axis, almost at the end during YAW tuning copter flipped and crashed (had to replace an arm and two props). Auto Analysis (Test: Brownout = FAIL - Truncated Log? Ends while armed at altitude 10.64m) so I decided my battery drained completely without further investigation.
Day two: updated to Ver.3.3.3 autotune = axis#1, after a couple minutes of flight copter flips again and crashes (stupid me, this time the frame is gone) and right before it hit the ground I could hear Pixhawk initialization tones,
Could someone help me identify the problem?
Looks like the board is losing power but this set up was flying OK for a couple years.
Here are both log files

I did not look at the logs, but yes, it may be a power problem.
pixhawk has redundant power option, use it.

Both crashes happened at the end of the Autotune cycle could that be related to saving / applying the results?

I recently read in who-only-knows-where, that if the pixhawk’s power consumption is too great, it will automatically reboot. It sounds like this might be happening to you.

Have you recently added any new gizmos to your copter setup that might be short-circuiting and causing too high a current drain or similar?