Cucumber Help?

Hello gardening friends. Could anyone offer advice as to what might be happening to my cucumber plants? I’ve seen no bugs or other pests at all and it’s not powdery mildew (at least I don’t think it is.) I’ve pulled a good number cucs off it already, and there are still plenty of little ones that are forming. The new growth looks really nice and healthy, but the old growth is looking scorched and crispy. We are in northeast Ohio, USA. They’ve been getting plenty of water regularly, and they are not in the same soil they were last year. I know they are probably overcrowded in this raised bed, but I don’t think that explains why they appear to be dying.

https://preview.redd.it/brnwm9wb4ped1.jpg?width=1080&format=pjpg&auto=webp&s=e247c94331a479947a4f0f7e1d02a63d80efc411

https://preview.redd.it/6v6obohc4ped1.jpg?width=1080&format=pjpg&auto=webp&s=20f33986467b606496a28bd62c0c8fb23e8bd7c3

https://preview.redd.it/l4gxrhvc4ped1.jpg?width=375&format=pjpg&auto=webp&s=0fbca0b05d9a9d6808393fbf112a1f732d57411c