Artificial intelligence innovations on the mathematical / algorithmic level are regularly not patentable at the European Patent Office. But their application to solving a technical problem is patentable. See here for more information.
The knowledge base includes many examples of patentable and non-patentable AI.
Bastian is a European patent attorney and a partner at BARDEHLE PAGENBERG. He specializes in software patents in Europe both from a prosecution and litigation point of view.