Thanks for the reply, I did some testing after the PIP changing by getting all chars to type /p f %f t %t to tell me what they are focussing on and what they are targetting. All of the focuses are on the new focus, apart from the old leader that still has himself as the focus. I don't know what else to add apart from that, but I would be interested to know the workarounds, the only one I know that does work is pressing the PIP focus key again which seems to solve this. I don't think it's a keyclone problem, it may just be that my computer can't keep up with the PIP changing and passing the command to the now lower priority window, but if I have to live with 2 key presses then so be it

Edit: Instead of a wall of text, the short answer: definitely focus change failing.