Female biting mate

Hello all! I have a 3 year old pair of Concentrics that were raised together.They share a 100 gallon stock tank. A few months ago the female bit the male’s tail almost all the way off! I immediately placed him in an isolation tank to care for the wound knowing it would be a slow process. It’s been 3 months now, tail is healed well, the stump is white. I attempted to put him back in with the female yesterday…within 5 minutes she latched on again. I was able to get him out before any more damage was done. Any thoughts on why she would start this behavior out of the blue? Will I ever be able to put them together again? I thought of maybe seperating the tank with some type of chicken wire so they could see each other but she couldn’t get to him. Any advice would be appreciated. They are absolutely gorgeous turts with beautiful markings…I just don’t know what to do about this! Thanks…Pat