How is your soil....Does it look good to you.?
Have you checked your corm and root health in the container.
Do you store these inside during winter?
Pop the plant out of the container and see if you have good root structure along the sides of the pot.
If your roots look unacceptable......freshen up your soil
These plants has been repotted in a fresh soiless mix and is slow showing recovery because root structure and corm health diminished during winter storage.
I generally treat(control) all my plants the same with fertilizer and soil yet I will get a couple that refuse to cooperate like his these .
So think it is a corm/root/soil issue and not a nutrient issue, just my guess.
Are you able to post a pic where you show the stem and soil together?
Notice the surrounding banana leaves all look normal .
Do your roots and soil look good to you.....I popped this out of a container for another post to demonstrate soil consistency and root structure.
