Observed Result

• Spruce is placed 2x2 and fed bone meal from a dispenser and it doesn't grow anymore.
• Since it is built into the device, the surrounding blocks may have something to do with it, but when I took the dispenser and manually planted the bone meal, it grew into a huge tree!

Expected Result

• I don't know what caused it, but if you fire bone meal from a dispenser, the spruce should grow into a huge 2x2 tree!