Leaf is face down

I planted 10pc of durban poison. I got up this morning. One of them all the leaf is down. I took it out of the light over night, today, It still same, What happened? I am using the same method to feed them.
Temperture 27'c at day light ,23'c at night
Ph 6.4
humidity 65

It be dying...

I watering everyday, the soil surface is wet

Quit watering it, the poor thing is drowning. They have to go through a wet-dry cycle. keeping the soil always wet is starving oxygen from the roots. Let it dry out a few days.

You are DROWNING them.

When you water, you should do so when they need it, not on some schedule you make up. You should let them dry out a good bit to where the pot is actually very light.

So lift the pot. It should be pretty heavy as saturated as it and the plant is.

Don't water it again for a while. The leaves will start perking back up in a few days. Some of them will probably drop off. That's OK. Once they perk up, lift the pot. If it's still pretty much the same, DO NOT water it. Wait another couple of days.

You should see your humidity start to fall off a bit and the pot get noticeably lighter when you need to water it next. Once you get to that point, you're golden. Water until you get a bit of runoff, then don't water again until the pot gets light again.

In the beginning you should only water once a week or so. As the plant gets bigger and bigger that will go to every three days, then every other day, then towards the end MAYBE once per day. It all depends on the plant.

Many Thanks for everyone

Do you water until you get some decent runoff from the bottom of the pots? You're obviously keeping the surface wet, but what going on below could also be causing this. Its called an antagonistic situation in the root zone. Where dry and wet zones meet. Just a thought in case you are not properly watering.