Do you know if your horse can jump that high? If not, don’t jump higher. I probably would have just done the same height again to get a clear round. You might also want to give her a longer break between your shows if she’s not putting in as much effort as she usually does or if she’s not used to your showing schedule. If none of these are it, I’d suggest taking a crop and using tons and tons of leg! You’ll be sore afterwards and it’ll be a pain during, but some No Stirrup November might help.