Are you sure they are not damping off?

I'd say give it a few days, and they won't be green anymore.... Also looks like damping off to me.

We're the seeds covered or surface sown? Sometimes if surface sown they have difficulty in digging down. I would hold by a seed leaf, poke a hole and place the root down in the mix, replace mix very very gently, and see what they do. Keep them a bit drier and warmer. You have nothing to lose by trying this.

Gill

When I grow agave seeds I find that seed will float to the top (I am a rough waterer) and grow sidewards for a while and the roots will bend and penetrate into the soil and then the plants will slowly stand up. My plants are planted in very fast draining soil. This process will take a month or more. I usually do not move them out of the 4" pots that I sprouted them in for 1 year. I am not a very careful mother of wee ones. I am telling you my experience, not telling youth it is the correct way. Usually, I plant seeds that I have a lot of that I collect from around me. These are not treasured seeds.