Hi have found what it looks a bug with Tokens and quite an annoying one.

I have tried to replicate with CoreRPG without any luck, but it is easily reproducible in SWADE. See linked video.

Basically if you move a token on top of another in the map it could cause the token of the target token to change to be the same as the one you are dragging on top of it.

https://youtu.be/aGfsYcR5ECc

Is there any way of preventing this? Maybe I am doing something wrong?

It is quite a problem when you have swarms etc around. :S