recalibrate the IGM(inverter generator module)
not to get fobbed off by any talk of a "software upgrade". This is not a SOFTWARE problem in spite of what the dealer will likely tell you.
After multiple "software upgrades on my car and at my insistence, the IGM module got changed under warranty and , hey presto, no more error messages!
Bear in mind that the T8 does not have an alternator to charge your 12 V battery, therefore whenever the Hybrid system fails , your 12 V battery is not being recharged and will deplete faster than you can imagine.
Your are very likely to be left on the roadside as the car will go into limp mode.
Admittedly, the module costs a lot and your dealer will try very hard not to change in it.