One issue I've noticed when I was soloing a battle leve yesterday is

After killing the first leve mob, I pressed TAB to target the second one in the same mob group. It happened that a mob from another leve mob group stood in the middle, as I tabbed through it it was targeted first ad hence the AUTO ATTACK started, which wasn't intended. Then I had two groups of mobs attacking me at the same time >_>' which I couldn't handle, so I ran away. Even if I could, I wouldn't kill them at the same time as the other group would yield no SP.

Sometimes there is a need to press ENTER to initiate auto attack, sometimes there isn't. Maybe only the first mob we need to press ENTER?