What motors, props and ESCs are they?
In @Allister s graph it looks like desyncs, because Motor 4 recovers, but Motor3 loses sync, then later Motor3 again and Motor 2.
I looked at log_9_2023-5-23-19-23-44.bin
Battery voltage is starting to drop around the time of that incident, approaching the low voltage level for a 6S Lipo, and you dont have the correct voltage levels set or failsafe actions.
And it looks like definitely Motor3 gave you the big trouble. So similar issues to the other log that Allister looked at.
Motor outputs have a small oscillation in them, and attitude control also has small oscillations.
There is all default parameters for tuning, so incorrect PIDs and lack of tuning could be causing the ESCs to overheat and lose sync.
You need to connect to MissionPlanner Initial Parameters and put in your prop size, battery cell count, select “Suggested settings” and press Calculate → accept everything it offers.
It is a mistake to think you dont need some of these “just while we are testing”
Then set these:
INS_HNTCH_ENABLE,1 // set this then refresh params to see the rest
But don’t rush out to the field to try all these new settings yet!
A big problem is vibrations.
You need Y axis and Z axis down below 20 at least, preferably below 15.
Something is touching or pulling on the flight controller to make the Y axis vibrations worse than X axis, or the antivibration system is not equal in all directions.
Z axis vibrations can take a bit of work to fix - it could be prop wash over the flight controller, frame or parts vibrating and resonating, just poor antivibration mounting - there is a range of possibilities.
Once you are sure vibrations will be improved → then head out for another test flight.
Show us that log and we will move on to next steps.