I recently got a Klingon bridge officer (engineering). I bought a bat'leth for him and took him into combat. I noticed he wasn't walking around with it out. Then we got in combat and I noticed he wasn't fighting with it. He was just deploying some turrets and doing some other abilities, then standing around doing nothing.
I thought maybe the bat'leth was the problem, so I gave him a disruptor weapon. I see him carry it around, but still, he doesn't fight with it. I never see him shoot it. He deploys turrets and does his other things, then stands around, not shooting.