Probably hasn't bulked up enough yet. After being released from pot should grow taller with each flush, if not it needs lusher conditions.

Of course, dwarfing conditions of container culture also what produces best swollen culms.

Mine didn't do much the first year, one shoot the second year and 6 shoots the third year.

Mine is in the ground--no problems with the swollen culms so far.

{{gwi:399861}}

Yes, either they are more bulbous in pots or that is just a myth. I haven't checked, almost didn't mention the idea.

Love that pic... mine have only been in the ground a year... they shoot up 6-7 foot, but only thick as yer pinky finger...hoping to se thumb sized this season :-)
Take care
CJ