Yeah, I run the cheap $6 Fotek brand SSRs, and I cannot let the duty cycle be 100% for very long or it "sticks" closed even when commanded to open. I have to shut off power completely for a second or two. If I keep the duty cycle in the 85-90% range, they work fine, no problem. So, I just limit my PID output to 85% and deal with it for now. It still heats up as fast as I need it. When they fail I will replace with a better quality SSR.