If you need it to stay as an ObjectValue, since it references the instance, you can change
if Owner.Value == PlayerName then
to
if Owner.Value.Name == PlayerName then
which should get the instance name—the player name. Come to think of it, that’s probably a better option in the first place than using a StringValue, since you can also more easily access other parts of the player. Try changing it back to an object value and using .Name.
Actually, it seems like you already did this in the script with the error, but simply forgot to in the script from the original post.