Oblofusc

My banana plants have a leaf deformation issue that seemed to come up as they got larger, occurring with my misi luki mat late last year and happening again now with them and now my ice cream. It only happens with the largest plants in the mat. The pups (most large now) seem unaffected. I'm not sure whether this deformation is caused by underwatering, overwatering, underfertilizing, overfertilizing, is the result of some mineral deficiency, or is caused by a fungus or worm.

I will try to post some pics but until then I'll try to describe it.

The deformation is apparent as the "tubes" of the emerging new leaf are coming out. There will be a whitish band or bands along the tube where the leaf seems real thin, like tissue paper, and when the leaf opens these areas manifest as splits in the leaf and sometimes turn into areas where there is no leaf material at all in that band. In severe examples the leaf looks shredded as it is coming out, and when it opens it looks like it went through a windstorm and it is not as broad. But it otherwise stays green, and new leaves emerge, usually deformed to some degree or another.

I live in north Florida and this had happened last year to my misi luki mat and this year too, and is now also happening to my ice cream. I thought it might have been peculiar to my misi lukis, but now I know it must be something else external.

The plants otherwise appear to be vibrant and healthy.

Tips, suggestions and comments much appreciated.