Aubergines 2021

My Black Beauty aubergine seeds still haven't germinated (from a sowing on 26/2) - I'm thinking I should sow some more (sure way to get the current ones to appear, right?).

They should be plenty warm enough in the propagator at 25ºC, which means something else must be wrong. Could be stale seed, or maybe I sowed them too deep? I tried searching online, but came up with very contradictory answers from "a dusting of compost" to "an inch deep" - the latter must surely be wrong, given how small the seeds are?

Hiya Eyren

I would offer some advice but as I'm on my 4th sowing I'll leave it to someone else