Corfile install, but work space is way small

Did you make the cor files with CorFile2 software?
It appears that a loaded cor file will not let you change the area, but yours seems to be an issue.
I followed the procedure and I didn’t have any size issues. It usually has a larger field than it reported to me.
My F254 is supposed to be a 175mmX175mm and it comes up as 208mmx208mm…
Good luck