Barrel horse, not switching lead

So i have a 7 year old horse who from what ive been told when i got her has had some miles on her when it comes to barrels. When i do them with her i can tell she really loves it and she is really fast and goes tight around the barrels. But the problem is, after the first barrel she doesnt switch her lead to go around the second barrel, she slows down and trots around them. I push her to keep going and switch but nope, trot but after that barrel she goes right for the third one no problem. When i do figure 8s with her she switches her lead fine but it seems once i put an object for her to go around she cant do it, i was wondering if anyone had any advice on what i could do? Thanks.

Sounds like she's not finished... more than likely, not ready to be running the pattern.

Easiest way to teach a horse to switch leads after the first barrel is to do a simple lead change one-two strides out. Not letting the horse trot for more than a stride or two...then go on with the left lead.

I have that problem with my gelding, but he has an injury on his left hip so he doesn't like to switch the leads. He can, mind you, but it hurts his leg so I don't make him. Perhaps this could be the issue?

But as previously stated, she could not be finished.