We had some acre issues one fall (2020 or 2021) when running it on the combine along with a CHN 372 receiver.  The suspicion was that the 372 was sending too long of a GPS string to the 20/20.  We harvested well over million acres that fall!  That problem has gone away and I'm not sure why.  I ran 2023 for several years and am now on 2025 with zero issues.  Is your install unique in some way? What GPS receiver are you using? I find it odd that you think you need to go to a 7 year old firmware for things to work.