When that 24 month extension expires in October, you need an I-551 stamp in your passport. 30 days before your expiration date (or more?) you need to try to make an appointment with your field office (or service center) for that stamp, which is valid for 6 months to a year, basically replacing your green card and extensions for the time being.
however, you won’t lose your job. You are in your employers system and only need to show GC status when you change jobs. For this, the stamp and extension letters etc should suffice.
depending on your field office, times for ROC are currently 22-36 months wait. I hollered for my congressperson and they sorted the chaos on my behalf.