An invalid unit order has been given

Good day,

I am playing the Double Trouble DLC campaign with a friend and we arrived at the second battle of Cherrystones, "Many a Mage"
We are almost at the end of the campaign has we played cherrystone as last.
My friend was playing the childs and got this error, as on his screen one of the cherrystone was there and by me no.
Now he get kicked out but as it is his turn I cannot give up and restart the battle.
How can we fix this?
It would be a pity to restart everything from the beginning
Please see attached my screen and his with our last scene.
As you can see on his screen there is no cherrystone aura while on mine yes.
We are both Switch player.
Thank you in advance for help