I am 9 days far with my kit and the pinheads are comin up really nice. But only on 60% of the kit. The left side has only pinheads on the sides. Not in the middle.
Could it be solved with spraying some water on the kit?
No, do not spray directly on the kit, it will stop pinning. The mycelium is looking for the fastest way to oxygen. This may be through the left side. Take a clean fork and scrape a bit of the top layer on the spot that is not forming pins to let it have acces to oxygen. If water is needed you can poor water into the sides.
You've probably already picked them, but in case anyone is wondering, you should pick the mushrooms on an individual basis, just before or just after the veil breaks (this is to maximize potency).