If just one of the ten LED lines is not wired up correctly– for example, if a solder joint has failed –you will start to see these kinds of funny lit-up patterns. And yes, it’s an effect of charlieplexing.
When you’re describing the LED positions, I’m not sure if you’re describing the locations of the LEDs that are lit up, or if you mean the opposite– the LEDs that light to indicate those times. But in any case, you should check each of the vertical LED line jumper wires, and especially the connections at the microcontroller and the resistors– those are the most likely places for the issue to be located.
