Al-Fiqh al-Akbar, the greater understanding, is one of the earliest documents that can reasonably be called an Islamic creed, and almost everything about it is disputed. It is transmitted under the name of Abu Hanifa, the jurist who died in 767 and gave his name to one of the four Sunni legal schools. More than one text circulates under the title, the recensions differ in length and in what they treat, and scholars have distinguished them by number to keep them apart.
The arguments run both ways and neither has won. On one side, the doctrinal positions in the shorter text fit what is known of Abu Hanifa's circle and of the questions live in Iraq in his lifetime, so a core going back to him or to his students is plausible. On the other, the developed vocabulary of the longer recensions belongs to later theology, and the transmission chains are not strong enough to carry the weight placed on them. The atlas marks the attribution as debated because that is the honest state of the question, not because a decision is pending.
What is not in doubt is that the text was received as Abu Hanifa's and taught as such for centuries. In a tradition where a creed's standing depends on the chain that carries it, being believed to be by Abu Hanifa was itself the source of its authority, whoever actually wrote the sentences.