Got my new FPV setup on the go yesterday and tried a bit of range testing. Had the FC-40 out to 1 mile from home point when the video started to become a bit too snowy so I put the quad into IOC Homelock mode and started pulling it back towards me. Video was patchy but in between the interference I could see it was starting to slowly move back in my direction. After some more video loss and reconnection, I started to notice that the quad was now flying at 90º from where it should've been and despite still pulling the pitch stick back to me, the aircraft was getting further away. Failsafe on the S1 switch sorted it out and it started coming back as expected. Studying the GoPro footage afterwards I could see the point at which Homelock gave up with a little wobble of the quad, some irregular motor noise and then its direction changing from the expected westerly bearing to heading south. I think it'd be wise to be very suspicious of Homelock if it can potentially cause your aircraft to fly in almost the opposite direction from expected when at the extremes of its range.