Yes, that can unfortunately easily happen to an otherwise harmonious pair when they are moved, or just even by re-decorating their tank
Do you have any fishes you can move to their tank as dither- or target fish? It sometimes helps, that the dominate has other fishes to spread his aggression on, instead of spreading them out the partner and it also strengthens the pair bond between the two
If things runs totally out of control, you could move the dominate fish for a while and give the other (properly the female) some time to recover from the moving and if it´s the female, time to produce some eggs, so she is ready when he returns
Another solution I´ve used a couple a times with X. spiloptera, is to lay their tank in complete darkness, covering it with towels or a blanket, for a couple of days
I’ve stopped keeping the bi-parental Xenotilapia by themselves in their own tanks, for the same reason – one of my X. sp. “fluorescent green” males is extremely nasty towards the female, and if there were not any tankmates he could chase instead of her all the time, I’m sure he would kill her.
Good luck with them