If you don't want to experiment with various amendments, go for a soil test. Even though you have amended soil in your raised bed, something is going on to cause the yellowing leaves. Other than that try adding some quality compost and see if that helps the plants out.

I have one that does that each year...Clematis "Daniel Deronda" that is planted against my foundation of my home ..I just sprinkle some epsom salts around him and water in..and he greens back up for me...Jeanne

I decided to try the epsom salts before anything else. I had them in the house. Also, I'm not emotionally attached to these clematis vines, they came with the house. I still don't know what kinds I have (six vines total). Last year they were eaten by the deer so they didn't all flower. Now they are in a fenced garden so they should be safe.

Thanks for the replies, if the epsom salts don't work I'll be back!