In NCAA football 25 there were major issues with this.
1. I tried to create a 12 team custom conference with 2 divisions of 6 teams each, and a 8 game conference schedule.
2. The way it is supposed to work. Is a 4 year treadmill...
You play each of the 5 teams in your division & 3 of the 6 teams from the other division. Who you play at home in year one you play on the road in year two. Who you play on the road in year one you play at home in year two. Giving every conference team 8 conference games 4 at home and 4 on the road.
Then in year 3 & 4. Everything stays the same except you switch out the three teams you are playing from the other division. To the three teams you have not played yet. Once again who you play at home in year 3 you play on the road in year 4. Who you play on the road in year 3 you play at home in year 4. Giving each team 4 home/4away games.
Then start the 4 year treadmill allover.
Problem 1: In NCAA football 25 when it came time to rotate to the other 3 teams from the other division. Only some teams would rotate. You would get stuck playing certain teams every year. And never playing other teams from the opposite division.
Problem 2: Some schools would still play 9 conference games while others would play 7. Even though you set it to 8 conference games.
Problem 3: Sometimes certain conference teams would have 5 home / 3 road games. Or 3 home / 5 road games. Instead of 4home/4road like to was set up to be.
I hope theses issues are fixed now in NCAA Football 26.