That's because EF doesn't know (has no way of knowing) that you're EXP. Which seats you can access (and when) depends on your status. Seats to which there is no "general" access will appear blocked on EF but will be available via QF if you have sufficient status.
Not sure that this is the case; within Expert Flyer within My Account, on the preferences tab, can put in FF numbers specifically for seat map access and it does allow entry of AA numbers into the FF number for QF seat maps
It definitely works with QF numbers for QF flights , haven't tried with AA ones