Dry, Crunchy, Brittle Leaves on my Potted Rose Bush?

[Ninasweetums]

Hi, I am new here but I need your help. I bought my first rose bush and planted it in a pot. I live in an apartment so planting in the ground was not an option. I planted it with potting soil, in an 18 inch wide pot that is very deep and has a water trap on the bottom. I placed rose food 1 inch under the top soil, not too close to the base of the plant. I pruned the dead blossoms off last week. It gets about 75 % sun per day. Yesterday the leaves started getting dry, crunchy, and brittle starting from the tips of the leaf to the stem. Please see photo. Can anyone tell me what is going on with my beautiful rose bush? I greatly appreciate any help. Thank you.
Sincerely, Christina.

[Algida]

Hi,
I can't explain it better than https://homeguides.sfgate.com/plant-leaf ... 75107.html
Here's what I'd do: repotting the plant and replacing the soil. Look for one recommended for roses. No fertilizer for about 3-4 months. New bought soils usually provide all the necessary nutrients for several months.
I usually leave new soil to dry (open the bag and leave it for a week or so) and then use it for repotting.
Sometimes new soils are over-moist and can kill a plant.
Keeping the plant under light, but not direct sun until recovered. Put the pot on a tray with water for maintaining humidity.
Can you post a picture of the pot (water trap)?