Px4flow firmware problem

Hello everyone, as the title mentioned
I’ve tried 2 versions of firmware, the first one is provided by wiki.
The readout quality value is always 255 even if px4flow is in a completely dark region.
I was wondering if other provided information is valid? (flow_comp_x ,flow_comp_y…)

The second version of firmware is provided by QGC (v3.3.1), and the readout quality value changes from scene to scene. I thought this version of firmware is more riliable,but this version cannot read the integral version of px4flow.

Since I am trying to implement drone hovering indoors by arduino based mcu,so the readout value from px4flow is important to me.

Is there any suggestion?