Try putting a small capacitor directly across each LED, to reduce the rise time of the current in the wire, this reduces the interference. Try a 100pF to start with.
Also ferrite beads on the connecting wires of the LED could also help.
Try putting a small capacitor directly across each LED, to reduce the rise time of the current in the wire, this reduces the interference. Try a 100pF to start with.
Also ferrite beads on the connecting wires of the LED could also help.