Update 3.7.21
For those who don’t want to read following report,……in a nutshell: Check your power module for poor soldering joint and especially the negative link (black) and it’s solder thickness.
I found the whole incident weird and initially couldn’t retrieve the .bin file as was corrupt due to sudden loss of power.
I then went to inspect the PM closer and found that in fact the positive connection (red) and the related components appear to be fine, yet the cable to the Navio2 was burnt out (insulation burnt off). But closer inspection revealed only the two GND wires appear to be affected.
Then I’ve discovered that the PCB track for the negative wire had in fact burnt out which in turn caused some excess current to flow via the GND wires and hence those burnt out.
I’ve been working with electronics for decades and seen information relating to PCB’s and high current applications where it is recommended to have at least 2.5mm of solder on those tracks to support the high current or in some cases a small copper wire is soldered onto the track for the same benefit. - Yet no such thing on my PM !
(Have attached a photo of a commercial electronic board where the tracks are much wider and many solder dots have been applied to support higher current (Navio cable shown for size comparison) – Yet that particular board is only expect to carry about 1/10 of the current that the Navio PM supposed to handle)
Finally managed to access .bin file and as everyone can see the total current came only close to 100A very briefly at the start of the flight but then stayed well below the rated 90A . - Yet still burnt out due to a weak PCB track.
The spike at the end was obviously created by PM and cables burning out and the subsequent shutdown of FC.
I would like to fix (simply solder negative connection) and test my PM. - Just to see if in fact still operational, not for actual use in drone due to safety reasons.
However, as the connection cable is not available as a spare part may not be able to fully operate / test it again. 
But having said that I will try the “Mauch” 200A PM instead as suggested by Marc Lebret.
So, check your soldering joints and PM.
…and then, happy, safe flying.