The arrow will look like it stops on top of the fence but it keeps going. You can tell if you pit a wooden button where is should end up connected to a command block with a say command.
MC-52681
Arrows Glitch When Going Over Cobblestone Fences
Resolved
Incomplete
0
Is this still a concern in the current Minecraft version? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases. If this has been done, we can reopen the issue.
Keep in mind that the "Resolved"-Status on this ticket just means "Answered", and that we are waiting for further information on whether this issue still exists or not. We will reopen it as soon as the requested information has been delivered.