Caucasian spinach (Hablitzia) germination

I’ve been trying to germinate Caucasian Spinach in the fridge. The instructions from the supplier was to plant in moist mix in pots in a sealed container and put it in the fridge for a month. In each of these pots I planted around 5 seeds. Only one sprout came up in the past couple days. I moved that pot out of the fridge onto a windowsill. But I’ve gotten nothing so far from the rest and I’ve also noticed white fuzz developing on the pots, probably due to the fact that they’re in a sealed container which I haven’t watered at all since the beginning because the water had nowhere to evaporate to. Yet doing this in a sealed container is recommended in numerous guides online.

I’m wondering if anyone he has tips and if I should be concerned about the fuzz. Thanks!