This has happened many times, to the point where today I just removed the quantum mines (Mk XII, rare) and put them in the inventory. But when I reinserted the mines in their slots, they start autofiring every 20 seconds again. In battle, I don't mind. They're at least doing something useful. But auto-firing (such as when I'm in the Solenae Dyson Sphere) when I'm not even clicking on their buttons? Maybe the mines are so overjoyed at being used they just autofire after their first daily use, until I warp out of the area? Odd, to say the least.
(It doesn't happen to my other characters, btw.)
Character info: KDF-allied Romulan science officer, level 65, Arkif carrier.
Today I've purchased Mk XII, very rare quantum mines and will experiment with them. Maybe the autofiring only happens with MK XII, rare quantum mines? Who knows.