Same thing here. When I first filled the feeder, a hummer came many times a day. I added more nectar (also homemade) and no more visits. I took it down, cleaned it, made new nectar, still no visits. I've done everything I can think of and I now see an occasional hummingbird but nothing like at first or even last year when they fought over this feeder, which was hanging in the same place as now. I know the nectar is correct, I know the feeder is clean, no ants or bugs or mold. I can't figure it out, either, but I keep watching and hoping they'll come back more often.