Oscillation at 40% / 44V battery

Hi team, I have built a large Coaxial

T-Motor U8 95kv 29”x9.5 prop

Batteries are Semi-solid state 12s 60,000

I am getting about 50 minutes flight time.

Tuning is not 100% yet.

For the first 10 or so flights when the battery get to about 40 volts, I am experiencing oscillations.

At first I was thinking this was something to do with the ESC,s hitting a current threshold and throttling back the motor. i.e. voltage reduces therefor current increases.

After talking to the ESC manufacturer, they say this is very unlikely as the wats are limited more than the current.

Over the last few flights, I am now seeing oscillation much sooner. Around 50% 44V.

I am far from the best at analysing flight logs but I think I am indeed seeing Roll vs DesRoll , Pitch vs DesPitch getting slightly worse while approaching 44 volts in this attached log.

Motor thrust data was collected at 48v giving me a MOT_Thst_Expo of 0.95. I am wondering is this is too high, and I should re-do the thrust stand data collection at 44v or even 42v?

It would be very appreciated is someone could look at this FL and advise me as I am struggling to work this out.

https://drive.google.com/file/d/1Kevf-NymUT808uDSJ3y2zDOEG4SQKvcL/view?usp=sharing

MOT_Thst_Expo of 0.95 is not realistic.

Can you share the collected Motor thrust data?

Sure, I am hunting for the file

Hi Amilcar, I am a little confused as I have re-done the spreadsheet and I am now getting 0.5. I am now not sure where 0.95 came from.
Please could you check this spreadsheet for me and see if you agree with 0.5
https://docs.google.com/spreadsheets/d/1cQNFkQ-LUgIKaY8Kvzid5koCDdanIFan/edit?usp=sharing&ouid=117385409066774504006&rtpof=true&sd=true
Thank you