Changing the screen, OEM replacement doesn't match up

My GF bought an iPhone 12 (basic model) off of a third party dealer on Amazon March of this year. About 4 months later the screen started to flash intermittently and the touch screen would become non responsive. From talking to folks, it sounded like it needed a new screen, so I ordered one. I took off the old screen using the ifixit.com video. Partway though I noticed the video and photo guide mentioned steps to remove a panel and a cable that attached the camera/mic/speaker assemble, but the unit I was repairing didn't have that assemble attached to the screen. I continued on and when I unpacked the replacement OEM screen, I found the OEM one had tabs on it, and screw mount points for the camera assemble I mentioned. The old screen had none of this, and the tabs won't fit into the body of the iPhone. I also noticed the old screen didn't have the two tabs towards the bottom that the two pentalope screws go through when you first start to take it apart. I did power up the unit after I attached the OEM screen and it works, but I wondering what the deal is with the differences in the screens. I checked the other iPhone 12 models but the base model i have does match most of the repair guide layout, but I cannot use the OEM screen. I'm going to try and get the serial number to confirm this is actually a real iPhone and not a counterfeit. Has anyone come across this before? Here are a couple reference photos. The old screen (I ended up breaking it while removing it) and the OEM one attached, the red circles show the camera assemble screw points, which are not on the removed screen.