What are the other conditions of the nuc? By your post I assume it is not growing. From what you have said no queen for at least
8wks. Can you post pictures? You say no eggs, do you have problems spotting eggs? Have you ever spotted eggs in a hive before? If you perhaps have vision problems, have you looked with a small LED light? You say no eggs so I guess no multiple eggs in cells. Just trying to explore the possibilities.
But............ most likely----You said July 1st:
>Thanks. I added another frame of brood to see what they do with it, I'll report back.
Are the new cells on a frame of brood you added July 1st? Are the queen cells capped. If so you are were queenless on July 1st and you are on less than day 13 (depending when the egg was laid in the cell) of the 28 day queen cycle again, from hatching to laying.