Try raising the lip so they can’t scratch things out. I’ve had that problem before and that was the fix. That also might make the nest feel a little more secure and safe so maybe they will start to use it.
If you had said 2’, I’d have said a perch is not needed. At 2-1/2 feet it’s a little more iffy. If they are getting up there to scratch the bedding out, they are getting up there so I’m not sure how necessary it really is. Still, I’d probably add a perch.
Since they have just started, are they laying in the same spot each day or are they moving around? Sometimes when a pullet starts to lay she seems to have no control over the process. She just drops the egg wherever she happens to be. Normally they gain control over the process pretty quickly and many have control from the start, but each pullet is different. If the egg is in the same place every day, she has decided that is where her nest needs to be. If she is randomly dropping them, raise that lip and put that perch on. Or maybe use something about 1-1/2” wide like a 2x4 to raise that lip and give them something wide to land on. The perch doesn’t need to be outside the nest box opening. They just need a good place to land. And keep the golf ball in there. Fake eggs do help.
If she is laying in a nest on the floor you can try a few things. If it is away from your nests, try putting a cardboard box, cat litter pan, or some type of open nest there for her to lay in. After she has started laying in it, gradually move it a few inches a day toward your regular nests. Once she is used to laying in the area of your nests, take the other nest away and see if she will make the switch.
I made some of my nests so I could lock a chicken in there if I wanted to. I’m retired so I am around most days. When I have a hen laying in the floor, I catch her on her nest and lock her in a nest box until she lays the egg. That usually takes about a half hour though I had one hen that took three hours. Stubborn hen. Most of the time I only have to do that once and they catch on, though I had to do that stubborn hen twice before she caught on.
Good luck with it. This can be challenging.