Certified GKH Gardening Expert
It would help to include photos! This is a product of nature, and completely normal if they are, in fact, seeds.
If these are falling over and have reproductive organs, and not actual seeds, then this will be a different problem altogether.
Floppy plants that are not seeded can be falling over for several reasons, including: too much water, not enough water, too much light, not enough light, and so on. (Contradictory, I know)
Pictures, and a good description of your care for them along with the climate in the immediate area that they reside will help me to help you better.
In the meantime, this article will give you more information on their care: https://www.gardeningknowhow.com/ornamental/bulbs/calla-lily/growing-calla-lilies-and-care-of-calla-lilies.htm