Overwintering nerine. It could be temperature related. I have a few pots of seeds grown clivias. They bloomed very sparsely when wintered at room temperature, but since I started wintering them in a cool greenhouse (+4 C minimum) they set buds and bloom profusely without fail every year. Now I have a couple of pots of seed grown nerine. They are not big enough to bloom, but it gives me some ideas. Bea Spencer zone 5 Ontario