Matrix output mixer displays audio level even though the paths output level is set to -120 dB

[somafan]

The matrix output mixer displays an audio level even though the output level of the signal path (the right-pointing arrow in the circle) is set to -120 dB and no sound is audible. The same applies to the pan control: even when it's set to "Left 100", both bars show a level, but the sound is only audible on the left. It seems to be a pure display error, but it's somewhat confusing.