The electronics of an AFCI are not intended to act like the "class A" GFCI protection required in NEC 210.8.
Now, that's not to say that an AFCI doesn't behave, in part, like a GFCI. That, an AFCI does do. It just isn't rated for the "personnel protection" required in 210.8.
(There is one notable exception that comes to mind. Cutler Hammer made a breaker that was both a Branch-Feeder type AFCI and a GFCI. But if you are wiring in an area that now requires the Combination type AFCI, then, you will find that no manufacturer of AFCIs makes an AFCI that is also a GFCI.)