I dont think this is a bad thing billie.... Think he is guarding eggs! or just found a territory that he wants to spawn in.... Thats exactly the way all my cichlids acted when guarding. The way to find out for sure is try to reach in the cave slowly, if he attacks your hand most likely theres eggs in there... well, or you could just look in the cave
For all the jewel guys out there, I just found out there are six different jewel variations... some are super red, in my opinion one of the best lookin cichlids around... then the more common ones are more dull in color... Just thought i would share that cause I went to a friends place and saw his breedin pair of jewels, they were expensive, and STUNNING!