Sometimes they do produce seedl*ngs that are similar to the parent plante. Seed strains, with named cultivars, are based on the premise that close pollination will produce a majority of seedl*ngs that closely resemble the parent.

But, since they are of hybrid origin, there are a number of "wild cards" that can be present!
Some Helleborus x hybridus produce few or no viable seed, even with hand pollination.
Others will produce variously colored seedl*ngs, some resembling the parent, many others, not so.
I have an old pink-flowered one in an isolated location in the rear gar-den, that didn't produce viable seed for many years. Once seedlings began to appear, they were all pure white. Seedlings from those offspring are predominately white, but with an occasional pink one in the crowd!

I have other very old H. x hybridus that have never produced viable seed.

The plants are monoecious, both male/female organs are present, so they are capable of reproducing in isolation.

Good luck!