Mine also started well and was capable of keeping the idle in the beginning. After a couple of minutes of working the shutdown happened (once at idle)
Does the ECU present any message after shutdown? Mine displayed minimum rpm reached.
Also if you think it is static, try to take and land over any isolation material like those foam pads for kids.
If you want, give a call 12-99119-8067. I have 45 our flying my wren 100.