Misfires in egg production and laying are VERY common with new layers! I had much the same experience with my Easter Egger, the first of my flock to lay.
Do be sure that they have a separate calcium supplement available 24/7, even if they’re on layer feed with calcium! Oyster shell is what most of us offer, either chunks (the most common form) or flakes (often preferred by layers; available on Amazon.) DON’T mix it with their feed. Different chickens want different amounts at different times, and their instincts will tell them when and how much to eat.
You can also save eggshells and feed them back to the girls. Many people sterilize them in the microwave, but after one attempt with the resulting stink, I abandoned this. I just save them up, periodically crunch them down, and sprinkle them on the ground where the girls like to scratch. Whether to heat them up, etc., is completely up to you.
Eggshells don’t replace oyster shells, though. Eggshells are metabolized quickly for a calcium boost, while oyster shells are more “slow and steady.”
But all the calcium discussion aside, what you’re seeing with your new layers is normal and common, and the kinks should work themselves out in the next few weeks. Don’t be surprised to find some double yolk eggs during this time!