OK the issue is that the power supplies are going being overloaded… The SimPliCity units had their own method of Trying to do a boost circuit like the SDR 480 has in that it would allow higher wattage for a short period of time which is what the 2 HUGE Capacitors are for on the board that the dual PSU’s go into.
The Problem is this boost is VERY short lived…
I am not sure How the power limit setting actually works on the IONI so I am not sure as to how it affects things… My guess is it just limits the Current draw causing the system to flatline at a certain current But maybe Tommi or Mika can explain better.
This situation does also occur very infrequently with the Large Mige and the SDR-480 where it will exceed the 720 watts and go into low-Voltage limp mode as you might say until the E-Stop is pressed when running Maximum torque… With the Large Mige and probably in your case as well the best option is to lower the MMC until the situation either occurs extremely rarely or not at all.
On a large mige this was a reduction from 25A (27.9Nm) to 23.5A(26.26Nm) based on what Tommi suggested I would probably leave the Peak Power limit at 400 but reduce your MMC from the 12.86 (20.01Nm) to 11A (17.1 Nm) and see if things fix if not you will have to go lower if it is not at a level of activation that you can deal with.
Note that doing this you ARE reducing your overall power of the system so in order to correct your Specific Output (at the wheel strength) to what you are used to you will need to lower your MAX FORCE slider by 15% or so (the same ratio as the power reduction at the wheel) otherwise the wheel will actually feel weaker to you.