SVMC72150 shutdown when throttle

[ElNino65]

Hi

I've got an e-scooter "PUSA 5000W" which runs on a SVMC72150 (I'm sure of that) and for the 5kW motor I've seen online that it should be a QS.
When I turn on the power with the key, everything boots fine: display, fan, controller red light is on.
However as soon as I turn slightly the throttle, the controller turns off instantly. The back wheel is lifted up so it can spin freely.
Some perhaps useful bits:

• When it turns off, turning the key on and off does not restart it. I have to disconnect and reconnect the battery and then it can be started again
• When the charger is plugged to the battery, when I start turning the throttle, the controller seems to shut down for a few milliseconds but start again instantly. However turning the throttle still does not turn the motor..
• I opened up the controller and nothing looks wrong/burnt to the eye (see picture attached).
• What started the problem: I live up a very steep hill, I hadn't taken the bike for a long time. When I arrived down the hill I felt that the bike was braking by itself, so I checked the brake calipers and one was indeed tight on the disc. I decided to go back home but that proved really hard (usually it was never a worry) and I abused the bike: full throttle but running very slow for a while.. at one point it stopped and when I checked the back of the bike there was some smoke. Could have been the calipers rubbing on the disk, I don't know...

So far I have:

• Disconnected completely the controller and measured the resistance with a multimeter across the motor phases. The value was the same on all the pairs: fluctuating between 0.0 and 0.1 Ohms
• Attempted to connect to the controller with the USB port and the MQCON program: the device kept showing as "Unknown" in my Device Panel despite me installing the CH341 drivers.

I'm looking for ideas on how to diagnose the issue. Thanks !