Sword glitch?

So I only have two enchanted diamond swords in my single player world. One is in my endermen grinder in the end dimension (that only has sweeping edge) and the other was in my inventory in the overworld (an op one with mending sharpness looting all that)

After dying to a vex, Id found that the vex had picked up my op sword when it died. After that, the vex ether died or despawned with my sword and it wasnt dropped.

So I go back to my endermen grinder a day later to find that in my chest, the sword with sweeping edge had been replaced by the one the vex died with. Nether of them had a name but I definitely didnt mix them up as the op one had fire aspect 2 while the other one only had sweeping edge.

I now have the op sword back but my sweeping edge is completely gone with no trace. Is this a normal glitch? Because Im honestly so confused at how this happened.