I have leaves that curl and seem a little brittle on some tomato and pepper plants in my garden, but not on all of them. One plant is over 60 inches high (in Iowa) and has tomatoes developing, so it doesn't seem to affect the growth. These are early variety, the other ones are a Roma type, and are not affected. Also have it on some pepper plants, which are all the same variety. I sprayed, thinking they might have aphids. I have excellent drainage, but the weather has been wetter than normal.
Leaves Curling on Tomatoes and Peppers
Certified GKH Gardening Expert
Tomatoes and peppers are generally affected by the same things. With this in mind, the following article may offer some possible reasons for your curling plant leaves: https://www.gardeningknowhow.com/edible/vegetables/tomato/tomato-leaves-curling.htm