Longbow attacks not registering.
This can happen if your screen is lagging compared to the servers: you see a living foe, the server thinks the foe is dead. So you’ll see your arrows flying, but there won’t be any actual damage. It’s hard to run controlled tests to confirm that is the cause, so you have to look for other signs of latency, such as delays when triggering skills or for pop-ups, etc (chat lag isn’t a good clue, because chat/guild run on a different server from combat).
You can also try asking Customer Service via a support ticket, so they can help track it down.
Sorry it’s happening — at best, it’s super annoying.
John Smith: “you should kill monsters, because killing monsters is awesome.”