The original icon has gone missing since then, but a few replicas exist, including the one currently mounted on the church. It has its own alcove high up above the entrance door - in the place where its prototype supposedly was found by the monks all those centuries ago.
I haven't heard anything about this particular one, but other replicas are believed to be miraculous. According to one legend, a religious procession had saved a nearby village and all its residents from a deadly air strike during WWII. The bombs were falling all around but none of them got inside the safe circle outlined during the procession.
During those times backpackers would stay overnight inside the caves and would burn fires to keep warm. They also couldn't help but leave notes of wisdom to future generations all over the walls - mostly the same "I was here" message. Some of the carvings ended up being so deep that up to 7 centimeters of surface had to be scraped during the restoration.
The main church doesn't have signs in it anymore, but some of the other caves still do.