The law in question: https://www.law.cornell.edu/uscode/text/2/chapter-17B/subchapter-II
The law prescribes allowances for delay, and prescribes recourse for excessive delay. The latter was not followed by those empowered to do so - which does not include House Democrats.
Where in the Congressional Budget is there a date set to disperse funds to the Ukraine?
Law is “end of the fiscal year” not “immediately”