So this is what I found today. Yesterday no hens layed in that nest box. Today the plastic nest egg was on the ground of the coop with bite marks and indentations (pretty hard to dent these eggs). It is almost like one nest box is being targeted at a time. I still don’t think it could be chickens for I’ve had that problem years ago and no what it looks like. It is almost like it comes in between 8 AM and noon. My chicken door is automatic 8” x 11” opening 1 foot off the ground.
Would a raccoon be so bold in daytime? I’m going to put my porcelain eggs in and let it break a tooth. Picture is different side of same nest egg.
If those eggs are as hard as you say they are you can rule out mice. Raccoons are seldom out in the day, but Rats are. You said you are in FL... there are other small mammals there too like muskrats. I think the only way you are going to solve exactly who it is, you are going to need to watch all day or get a game camera.
Nice thing is you can rule out chickens at this point unless your hens have sharp little teeth!