I tried to enter my farm today and my wheat is right next to my fence gate, so when I opened my gate, before I was fully through into my farm, I collected my wheat. The gate shut. I tested this theory multiple times with a dirt block and it appears that whenever you destroy a block that is next to an open fence gate, the fence gate closes.

I didn't expect anything to happen except that the fence gate should stay open

When I opened my gate and hit my wheat, the gate closed. I then tested this on a dirt block and had the same result.

Steps to Reproduce:
1. Open a fence gate
2. Place a block right in front of it
3. Break the block you just placed