Arduino for STM32

Having a really strange issue at the moment reading some voltage values.

I've designed my code to read 12bit values (as per mcus spec) but my expected values are a quarter what they should be. Setting my function to run as 10bit mode shows the correct value (though off by 100mV)
Is stm32duino layer truncating the values to something more Arduino like?

if so is there way to stop it and use the full 12bit range?

Even of conversion is done 12 bits. It is mapped to default resolution. See https://www.arduino.cc/reference/en/lan ... esolution/ to change the mapping.