There is a mistake in LEDS_INV_MASK definition:
PCA20006.h / nRF examples 10.0.0
#define LEDS_INV_MASK 0x11111111
// blue will be erratic
PCA20006.h / nRF examples 9.0.0 and older
#define LEDS_INV_MASK 0x00000000
// all erratic
However both are wrong and it should be:
#define LEDS_INV_MASK 0xFFFFFFFF
or
#define LEDS_INV_MASK LEDS_MASK
Regards
Hakki Göçeoglu