Intermittently my MP3 will will become very slow in all axis, I usually notice it does this when I’m panning, it’s as if the sticks are set to to the slowest rate but they are not. Sideways flying becomes painfully slow as does forwards and backwards. Landing and switching off and on normally fixes this but I’ve had a few hairy moments for example the MP3 was over the edge of a cliff in Mid Wales yards away (hardly any wind) but wouldn’t come back. It did eventually and it has done this a few times now. Anyone else had similar?
MP3? 
Do you mean the DJI Mavic 3 Pro or the DJI Mini 3 Pro?
I think it’s the Mini 3 Pro, as shown in his profile.
I have had similar several times but only in wind. Where the sticks to not respond to my actions. Even happened yesterday at Silbury Hill. I was trying to climb, but it wouldn’t listen - just stayed at the same altitude.
Sorry Mini 3 Pro
Share the Airdate from one of the flights when the fault occurred
characteristics you be feeling would be similar to ESP settings low values but the rebooting fixes this for short while seems weird. Is this happening when changing from cine normal or fast mode if so are you sure you have correct values for each mode and not thinking one stting is covering all.
If persists check Firmware and maybe reinstall firmware again to be safe.
Not sure your flying habits but there is the IMU, Compass, and Gimbal to consider especially the IMU could be giving you the errors your feeling, if you traveling more the 30+ miles plus from last location or a higher elevation then definitely do a calibration on all 3
Finally reset the drone if persists
Have you tried switching the mode to sport and back I had similar once and that either fixed it or it happened to fix at that time and fooled me into thinking that.
I’ve checked all the calibrations and settings, I’m just wondering I wear a smart watch sometimes Amazefit - I think it emits quite a bit of RF. I know this as it has a tendency to set off store exit alarms ! haven’t stolen anything honest ! You mention your will become slow in all axis - did you find the cause ?
You’ve probably solved your issue as it’s recommended not to where a smart watch especially with magnetic band. I’ve never owned or been up close to one so don’t know much about them but I know it definitely muck up your compass giving errors and definitely not be able to do a proper calibration.
Your the one best testing with it on and off, be great to find out results.
I’ve not had any issues since I’ve stopped wearing my smart watch at the same time.