Functional difference between JLLN and ANL type fuses

One thing that is interesting: After removing the bad fuse I checked it again. It acts like a diode. I get continuity in one direction but not in the other. Never seen any fuse like this. Can anyone explain? I replaced the fuse with a jumper just to get my psw inverter install completed and checked out. Should have proper replacement in a couple of days.

This is definitely not a common item. Called five electrical supply houses locally and none of them had and access to acquire it.