Bananas.org - Rot in stem/ wilting leaves

Hi

I'm hoping for some help with my bananas

One has a hole in the pseudostem just at ground level. Also some mold like "cotton"spots.

The others lose their bottom leaves on leaf at a time. Always the same way:

The edges turn dry brown, the outer half drop downwards, lose water tension, turn yellow and wilts in a soft moist way instead of drying up.

The large pot is the old one, I just repotted thinking it might be too much soil, causing the rot.

There are no small mites or any of that kind.

They are all in plastic containers, mixed potting soil with 40% Leca clay pellets for drainage.

I have given them an organic fertilizer once a week, but due to the curling leaf tips and shriveling edges I bought a 7-4-14 instead in granular form. I have mixed some in the soil and watered with a solution.

They are in a southsoutheast window and put up a new leaf in little over a week.

I know I sometimes overdo things - and get overzealous :)