i would not keep them covered after they sprout.

They grow a lot faster/better this way with both bell pepper and hot chilles, like I posted this is what works for me.

My house is between 18c-20c most days and they're getting a good six hours of direct sun and 8hrs of in-direct.

For people saying the're chillis have stopped growing I'd suggest trying this. I've only just started but Ive other ones that are half the size.

I only put a piece of plastic wrap over my seed-trays while the seeds are germinating.
As soon as I see green emerging from the soil, I remove the plastic. My seedlings show
incredible growth, even with my rudimentary light set-up.

Humidity is a major killer of pepper seedlings.

Josh