Cant drag slaves across water

I dont know is it a bug or not, but it is impossible to drag slaves on rope thrue rivers and water in general. If it isnt a bug pls consider making it possible to cross deep water with slaves on ropes.

It must be a bug. I drag them through the water all the time.

it is possible for me to drag them throught the water, but not to swim with them,when i start swimming slaves just cut loose and chill on the shore.

That’s true, we can’t swim with them. I don’t think this will be changed.
Your off-hand needs to be free to drag them, so you also drop them if you try to climb or switch to a two-handed weapon.

To get around this, think about building a horizontal elevator or a bridge across frequently traversed water.
I built an elevator just for transporting thralls over the wall between the desert and the highlands.