When Loka first updated to 1.15.2 the Arcanum was bugged and you got the same 3 enchants, but they fixed this. Upon fixing this bug another one was created because now it gives max enchants whether its protection 4, sharpness 5, or fire prot and blast prot, etc. It also tends to give you a different enchant, for example if it said Sharpness 5, it may give you a Smite V looting III for example. I just wanted to put this here because I and others have reported this since 1.15.2, but it still hasn't been fixed so hopefully it hasn't been forgotten.