Many times a plant with variegation is sort of weak, and an all green shoot will take over. The think to do, assuming you value the variegated sport, is to cut all the non-variegated shoots. Otherwise, the more vigorous normal growth will take over. Some plants even have reversion, that is, the variegation disappears and all new growth is normal. I hope this is not what is going on.

wow, I didn't know this. Yeah, I bought the plant for the variegated look it had. I didn't know that there was a potential it would just become solid green on the new growth. Kind of disappointing!