You may be feeding them too well. Try leaving off the feed or using just a high potash one .

Also make sure that they are getting enough light. They don't need direct sun, but they do need a fair amount of indirect light, or filtered sun to bloom. They do tend to bloom more in from fall to spring, anyway.

Mine is on a North windowsill and get no direct sun at all, and it has had five flowers this autumn. My mother before me kept the same plant on top of the piano, several yards away from the patio doors. I have to confess I neglect it a bit - sometimes it only gets watered when I notice it looks a bit droopy. I think Cherry is being too kind to hers!

That could be. They aren't entirely happy unless the top 1/2 cm of soil dries between soakings, though I have learned not to let them droop. May be more traumatic in our low humidity, though.