It won’t show improvement immediately after a watering, usually the next day it starts to visibly improve if it needed a drink so fingers crossed you have a positive update for us soon :)

The leaves curling up does tend to be an underwatering sign but I also have this issue with one of my two BOP. The leaves are curling up slightly but the soil is still moist under the first inch and humidity is over 65% (working to get this down!) so would be interesting to see what others have to say too?

The bottom leaves look burned. When you move plants outdoors, think about advice about getting a tan - start at 15 minutes full sun and add more time each day. Same thing goes for plants that are indoors for winter. Start in shade and move them to more sun over a couple of weeks. The plants and you will be a lot happier. PS - if the leaves are burned, just cut them off as the plant will generate some new ones to replace the ones that you cut off.

Do as I say, not as I do - HAHA! I moved this tree philodendron outdoors

I don't take a lot of pictures of my tree philodendrons but here is what this same one looked like April 25 this year as I was prepping it for summer.

This happened to me twice. Once when I put the plant outdoors on a sunny day on the west side of my porch and another time when i moved it directly in front of a west facing window. The leaves curled in within an hour.
I moved it back to its original spot, did not give any water because the soil wasn’t dry and the plant returned to normal within a day. I wouldn’t cut those leaves just yet.