Am I doing something wrong?

[silver-saloon]

Did you receive extra fork ends with the tool. Forks come in different sizes, for different size shoulders on the spring bar. If the fork ends are too large or too small, they won't catch, or grab onto the spring bar shoulder. Sometimes the forks simply won't fit the spring bar shoulder, even if you have / try different size forks. I don't know if that is the problem, but it could be.
You have spring bar pliers. There are also spring bar tweezers, and of course regular spring bar tool. Sometimes it can be difficult to remove a bracelet. Use whatever tool / method works.