Just a thought. Are you over riding the very low jumps and feeling anxious approaching them?
I get it, riders and their trainers often want the rider to over do the big release and two point to perfect the position. Good idea. BUT it can confuse the more ambitious horse into thinking they need a big jump. Seen it often. If rider is also anxious, it can get horse anxious…kind of a “You mean you are scared too
” kind of feeding off each others anxiety. If rider gets jumped loose or off it gets worse.
Made the same mistake myself when I first switched from Western (for 20 years) to Jumping. First trainer put me on an older lease horse, former 3’6” Eq veteran. She had me staying off his back giving a big release and had me successfully showing 3’ Adult Hunters in a year. That horse was slab sided with a flat jump, as are most Eq horses. Auto leads. Easy to stay with. Just needed to steer and tell him when to stop hunting the next fence. Very polite.
Moved and found new trainer and fancy, ambitious lease horse. Trainer told me he had a big round jump, we went to a simple 2’6” fence, I went into two point, gave a big release and he rewarded me with the big, round jump I asked for. After trainer rounded up the horse and I spit the dirt out of my teeth, trainer sentenced me to correctly executed flatwork, flatwork, flatwork and more flatwork including no stirrup work ( I was 50ish). I needed to seriously strengthen my position so I could stay in the tack. Actually enjoy flatwork (weirdo) and am good at it. Got to know and trust that horse.
Trainer also put me on some schoolies and sale horses for jumping and taught me how to just sit still and lope over 2’ fences, poles and cross rails with no change in position or rein. After about a month, got to jump my lease horse again and voila, no over jumping. Because I learned not to ask for it, was strong enough to stay in the tack and was not communicating anxiety.
OP might want to ask her trainer about how to strengthen her position, not be afraid to drop stirrups even if just at the walk. Would just suggest just trotting over poles. Flatwork, flatwork etc. Get to trust each other and get stronger in the tack before jumping again.
Have heard many well respected clinicians up to and including International level veterans say that novice riders tend to over ride and over release over tiny fences and that a full two point and big release is not really necessary jumping very low fences. We do these things to allow the horse to reach out in front, push off behind and use its back over a jump. They are not needed when the horse merely canters over with no actual jump. Yes beginners need to learn the positions and releases but that needs to happen before they see any jump requiring actual air time.
Ask your trainer about this…maybe some dressage lessons? Good HJ trainers should have a pretty good understanding of basic dressage and the basic, correct flatwork foundation needed to get horse and rider safely around a course of jumps.
My advice is based in over 50 years of mistake after mistake after mistake in two disciplines with various breeds and types of horses. Not miracle turn arounds.
In the case of my lease horse with the big round jump? I needed a basic transportation model but leased a Ferrari. I did learn to drive that Ferrari but every horse since has been the basic model moving up to a Cadillac. A Cadillac with a FLAT jump- cute knees but no crack back.
OP might be happier with a more conventional jump style she can be comfortable jumping it and not need hours and hours of strengthening saddle time and practice to learn to drive her Ferrari.
Its possible you bought a Ferrari for a sensible small car’s job.