Hi
Ive heard a few iffy things from other grow friends about rqs, but haven't had any experience myself. I think that every company has the occasional dud or runt. Hows the drainage on the cup? Does the humidity cup have a couple holes for air? It may also be responding poor to the 600 watt light?
Give it a couple weeks to pull through and then remove it if it doesn't improve. Some of my seedlings had a rough start but a great ending.