Lange Anna - Positive LEDs on channels B and C not lighting up when checked in circuit with multimeter

I'm not sure if this is actually an issue because this module is unfinished (all SMD components have been populated, no through-hole components have been populated). All positive LEDs light when I check any of the positive LEDs in channel A. Same with all/any negative LEDs in channel A.

On channels B and C, only the negative LEDs light. I have checked the polarity of each individual LED multiple times out of circuit and they all work. If I check the positive LEDs in circuit on either channel with the probes of my multimeter in reverse, the negative LEDs of the relevant channels light.

Is there actually a problem or is this expected behavior considering the PCB is not fully populated and is not receiving adequate power to run it? Thanks in advance.