This may be caused by the cold temmperature. It should be about 70 degrees in the house. Lower would cause the plant to stop growing.

It may also be root rot, causing the leaves to rot. Take the plant out of the pot. If you see no white roots, you need to shake off a lot of the soil then add fresh soil. Remove the two leaves that are rotting.

Nancy

I had a similar problem but mine not only drooped but curled badly, I found out that mine were sensitive to the artifical light and had to move them farther away and they came out of it. But with yours its a different problem, your plant looks healthy other than the leaves drooping, I would think it would have to get very cold in the house for that to be the cause say below 65. Id follow Nancys advice.