It could easily be an overwater. I mean the root system has been growing for about 3 monthes and has been maintaining all the plant matter and bud, now all of that is removed so the water needs of the much smaller plant now is much less, but the root system is still gargantuan compared to the plant matter. It should be fine, might just take a while to show real growth signs. If new shoots are starting to come in, then it's on it's way to revegging and just be patient.

Some plants take longer than others to reveg. It depends on the plant, some respond to changes in light cycle faster than others. Usually the ones that show sex earliest are the ones that'll reveg quickest and with fewer problems.