The bio humic acid you used ( i think) is basically a soil amendment probably with micro & macro plant nutrients and very little or no (??) N-P-K fertilizer. Bio humic acid is not soluble in water with acid ph. Your potting soil should be in the range of 6 to 6.5 (acid) for bananas. Check the ph.
We have a product called
Miracle Grow. I don't know what is available in your country, so cross check this to similar products available to you. .... Just mix at 1/4 to 1/3 the strength as directed for potted plants and spray on the leaves every 2 or 3 days. The banana will take in the spray within minutes. Be careful of how much water you add to the pot and not over-water the roots. ... This will help to get food to the plant while solid fertilizer is being slowly (weeks) taken in by the roots.
I can't help much more. Contact
stalewiak by PM may be he can help more.