Both Logic in Computer Science (Huth and Ryan, 2004) and Branching vs. Linear Time: Final Showdown (Vardi, 2002), state something to this effect (paraphrased):
In LTL, X F p and F X p are equivalent, meaning "p is eventually true in some state that is not the current state". In CTL, AX AF p and AF AX p are not equivalent. AX AF p does mean the same as the above LTL formulas, but AF AX p means something different, which we leave as an exercise to the reader.
Both works emphasize that the meaning of AF AX p is something very strange.
From what I understand of CTL, AF AX p would mean "all paths from this state eventually reach a state where p is true in all next states", but that doesn't seem particularly strange. Am I correct in that understanding?