Why are my African Cichlids and common Pleco fighting?

I know the answer to this, but I need advice. My 6" common Pleco just recently started getting picked on by my African Cichlids, the biggest one being about 4". My Pleco, who I will now refer to as Carl, cuz that's his name, unfortunately decided to pick the same dwelling place as my biggest Cichlid, which btw is your common blue/yellow mixed African. The Cichlid chills out in this hole in the rock, and Carl stays on the other side of the rock. The Cichlid must have noticed that Carl has chosen this to be his territory, because he is constantly and viciously picking at his fins trying to pick a fight. Instead of fleeing, Carl just sits there and takes the beating, occasionally thrashing around to fight back, but never leaves his spot. It saddens me to see this because we've had Carl for quite a while now, and there has never been any kind of aggression towards him, because he minds his own business, as most Plecos do. Since I didn't wanna come home from work to a dead Pleco, I have fished him out and put him by himself in my 26 gal bowfront that has just been recently set back up and cycled. Anyway, I want this to just be temporary as I need to move the decor around in the Cichlid tank so they could establish new territories, but I don't want this to be a recurring problem, because I just love having a Pleco in the tank. Any advice as to what I couuld do?