Hi,

You can’t measure at M3 directly. It has a very high impedance, a multimeter or an oscilloscope probe loads the voltage down so much. You would need a voltmeter with a input resistance of 100 MOhms at least to get meaningful results. And you’d need to measure not at M3 (anode) but on the cathode of the diode. You can instead use scope or multimeter across R4 and multiply the reading by 214 to get the real high voltage value.
That M1 measurement looks weird. It has only 2,7 volts peak-peak. That should be more like 3.3 to 3.6 volts. Frequency looks good.
What you can try: with the KIT1 turned off, check the resistance of the connection R3 to R3 (the 2 10Mohms resistors) to ground. It must read 10 MOhms.

I hope I can find some time for your firmware tomorrow.

Cheers,
Wolferl