I believe they need more sunlight. Although they are promoted as shade plants, they do well in full sun and many species in the wild grow in meadows, so not under the canopy of trees. Can you move them to an area with more sun?

yes, these plants are only shade tolerant, not shade loving and most varieties will grow very well in 4-6 hours of sun daily or more. These are not really woodland plants in nature but are found in woodland verges, meadows and rocky screes. Some species (H. argutifolius or Corsican hellebore) are even found in full day sun in hot, dry climates!

Unfortunately this shade deal is a reputation/myth that does growers no service. A lot of shade inhibits the flowering of most plants.