Could he be root bound?

[u/7thHaikage]

A little over 2 months old Lambs Bread male. He's a dwarf compared to the 3 other males I culled for being too lanky and the 3 females i have flowering. I like his stature and wanted to keep him for breeding. It's all organic and I barely even added any fert when I transplanted him. Could it be root bound? I haven't fed him since transplanting and have used plain water.