Troubleshooting the counter arc circle: Your horse’s response will be affected by his natural asymmetry (his stiff and hollow sides), as well as by whatever magnets are drawing his attention at any moment. As when riding a regular circle, use the key-in-ignition movement to correct a collapsing circle with your inside leg at the cinch, and your outside leg at or behind the neutral position, as need be to adjust the position of his hindquarters.
Be sure to keep your counter arc circle symmetric and round. If it becomes like a cigar in shape, know that your horse has a strong magnet probably on the part of the cigar that’s furthest from the barn/gate drawing him back to it. And, when you’re closest to the barn/gate, it’s probably hard to move him smoothly on the circle, away from the barn. The challenge is to smooth and round the circle out.
The parts of your horse that aren’t working correctly are his shoulders and his hip. The hip is usually worse and isn’t moving off your outside leg. So, when you go from circular to cigar, slow it all down and make his hip move off your leg in an exaggerated side-pass to over-correct. Then, move back onto your circle track. You’ll know you are losing control if you find you’re cranking his head too much to the outside. It’s our natural reaction to counteract them not moving off our leg, so just a little bend of his head and neck to the outside, accompanied by an aggressive outside leg.
Be patient and keep working on symmetrical circles and counter arc circles, and you’ll be surprised at how much control you’ll gain over all of your horse’s body whole body and mind!