Gloi
Too little time, too much to read.
OP You are on a loser expecting it to canter, just stick it back in the cart where it knows what it's doing.
He actually struggles to pick up any kind of semi decent canter EVEN MORE SO when he is out hacking or on a straight line because that is when, in his trotting days, pushing him on would just mean extend and speed up the trot. It is quite obvious that a lot of people who have chimed in on this thread have never had ex-trotting horses before. He is not a green horse, his walk and trot are completely established and beautiful quality! He works in a gorgeous frame and works very fluidly through his back. He just spent the first 7 years of his life, not being allowed to canter.
I have a trotter x cob. There’s a knack to riding him. You have to make sure he is really connected and collected in the trot to achieve a good canter. Allow him to trot flat with his head like a giraffe and he goes disunited with his back legs together at the same time for 4/5 strides. Feels like he’s bucking.I have a trotter x and he had absolutely no idea how to canter and was so disunited. I ditched the school which he hates anyway and used hills to get him going. He is so much better uphill, he still prefers to trot on the flat but when really excited and hacking somewhere new he will go from walk to canter a lot easier.