I think you need water, if the ivy has an abundance of dired or wet leaves and pine needles under or over the ivy my grandfather said the ivy could not receive nutrients from the soil as debris is between the ivy and the ground. He recommended using a blower on top of the ivy, and gently lifting the vines to brush out the dried leaves or pine nuts, etc belwo the ivy, a rake is not recommended, put on some gloves, high boots, walk on it for awhlie to scare away snakes if there are any, and get down on your knees to lift and cleanse undter the ivy. Our ivy is 80 years old, still saving the bank from erosion. it is profuse ans was actually torn out and stolen, from wides swathes of the backyard. You need to water the ivy In order to save ours after destructive negihbors tried to remove it from a bank in our backyard, I left the water on all night.
I don't recommend leaving your water on all night, but at least get a sprinkler on a very dry day then leave it on for at least 15 minutes.
Good Luck