ML is one of subdomains in the AI field, so instead of "sometimes overlap" it's technically correct to state that ML is a strict subset of AI.

What you use as description for AI tempts me to use the "use it as a buzzword" angle back at you here - it is a stereotypical description of some use cases of AI approaches; but there are others - [machine] learning, knowledge representation, planning and scheduling, reasoning (both formal logic reasoning and also reasoning under uncertainty e.g. Bayesian approaches), intelligent agent representation, etc, are all parts of the AI field.