We have AP 1240AG connected to LAN via media converter AIR-PWRINJ-FIB.
When there is link failure on the fiber side of the AIR-PWRINJ-FIB the cooper port on the media converter is always up and did not detect fiber disconnection effectively AP1240AG did not detect LAN connection failure.
Is this a normal behavior of AIR-PWRINJ-FIB?
This is normal in install Ihave seen. the issue is the ap does not communicate with the far end switch in spanning-tree. What some have done is put switches on both ends, but that might be costly. You might want to search around for a converter that might have the ability to do this...
This sounds like it can do what you are looking for: