A level 32 not max affection 6* is easy to kill. Espacially on event maps. Event pests are way better than main missions pests of the same level (and above). I think you speak about the second phase of the current reissued event. Pests on this one are strong, even on beginner mission. It's not that surprising. Just remember that event are hard for new players and need a certain amount of total power to be done without troubles.
The only advices I have are:
- Boost affections of your best girls.
- Take a powerful ally to rush the mission.