Lead says async func in useCallback is incorrect, use useMemo instead, WTF?

Hello hackers! Normally I would discuss this with the team but it's just me and our Tech Lead on the FE so I'm posting here for my own educational purposes.

I submitted a PR review containing an async function in a React useCallback earlier and our tech lead mentioned that:

"You can't async useCallback, it can cause unexpected behavior. To achieve a memoised async function instead use useMemo".

It was always my understanding that useCallback returned a memoised function and useMemo a memoised result or am I missing something here?

The asynchronicity should also be irrelevant or?

Any feedback would be appreciated, thanks!