Mine are slow to flower this year but I see buds about to open and this morning I was greeted with a gorgeous white cosmos, there are purple, and pinks about to bloom to, my friend is like you, she bought seeds for her parents when garden centres were closed and she never had cosmos (it was on my suggestion she bought them) and her parents think she got sold weeds but I have been sending her updates of mine and today she says there is buds and they are about to bloom, just have patience I would say