بسم الله الرحمن الرحيم
There is a minor difference between Ash’ari and Maturidi. They differ only in a few issues. Hadhrat Maulana Qari Mohammad Tayyib, may Allah have mercy upon him, former Mohtamim of Darul Uloom Deoband, in his book “Ulama-e-Deoband Ka Dini Rukh Aur Maslaki Mizaj” states:
“As per the Ulama of Deoband they are known as Maturidi but a group from amongst them is of the view that they are Ash’ari. Firstly, they are attached to Hadhrat Imam Shah Waliullah of Delhi. It is understood from his books that he is Ash’ari. Hence they consider the Ulama of Deoband Ash’ari. The second point is that the senior Ulama of Deoband respect and side with Ash’ariah in their lectures, speeches, writings. But if, in view of their tendencies towards both the Maturidiah and Ash’ariah, they are called pro-Ash’ari Maturidis then it shall be in line with their scholastic mode. Rather they seem to be combining the Ash’ari and Maturidi schools. Moreover, their comprehensive discussion shows that the differences of Ash’ari and Maturidi schools are just verbal dispute, not real differences. (P. 156)
For more details it would be better to study the above mentioned book.
Allah knows Best!
Darul Uloom Deoband
This answer was collected from the official ifta website of Darul Uloom Deoband in India.