I have some of those too; my remedy is --sealed jar with moist paper towel on the bottom. Let the seeds rest on top of towel and replace the paper+water every 2 days so they never start to smell. Low ppm water, no added nutrients GL! 👊😊 The more seeds the more important is the water change, to prevent mould etc.
During my hemp project I had roughly 100 seeds behaving like this out of 1000, and only about 70 germinated within 48h without any issues. Lots of green seeds, and very dry seeds, still floating after 24h; probably some old batch :P
Moisture and don't drown them, they need to breathe 😋
Dark or light didn't matter for germination, lights aren't strong enough to shine through the shells, unless they are cooked in the sun😎