Follow-up: 12 sessions of laser hair removal but doesn't seem to work? (photo)

Hi, I'm male with dark coarse hair and pale skin. I have had 12 sessions of laser hair removal for my beard. After a treatment, it looks like it worked. Hair falls out and grows back finer but eventually goes back to its normal colour and thickness. They use a nd yag laser type on me. From the picture I'm showing you will see bald patches. This was due to 12th treatment and the hairs you see wernt affected by treatment but they used to be lighter and finer but now back to normal. Why is this?