Just booked ORD-AMS-CPH (stopover), CPH-LHR-ADD-SEZ, MUC-ZRH-YYZ-BWI

I tried to add more 23 hour stops in Europe (total 10 segments) but the computer kept getting an error.

I was told max is 8 segments on a single ticket. You can have more segments, but you have to do 2 one ways but then you lose the free stopover. Not sure if this is a new hard and fast rule, but every time I tried to do more than 8 segments, I got an error.