Hi - my guess the point of growth died and the new shoots are coming from secondary buds all over the place.

What I would do - leach the pot, repot the plant in a fresh soil and get it covered. In a month when suckers will grow bigger - you can disassemble the mess - and root them up.

The new shoots are healthy - so I do not see any bug problem right now.

The miniatures have miniature species trailer in their ancestry - so if stressed - they sucker very easily. The minis need to be repotted every 4 months - because the pots are small and the soil gets used faster - and old soil stresses the plants. The growth point can die on any plant for several reasons - for example if you sprayed against bugs - and the plant didn't really like the insecticide - and sometimes you just do no know why.

Good Luck

Irina