What is the ruling on making up an inverted fast due to ignorance, and is it sufficient, and is it obligatory to repeat it after knowing the ruling, given the difficulty of repeating it?

Whoever broke their fast out of ignorance is not required to make up for it (qadaa'), though if they do make it up, it is more cautious. It is not necessary to observe sequential order when making up for two Ramadans; one's obligation is fulfilled even if the second Ramadan is made up before the first. For making up fasts, it is sufficient to have the intention of making up a fast (qadaa' fast) without specifying which Ramadan it is for. Any fast observed with this intention in the past is valid and sufficient.