hello steven,
i created a month ago a world league too, using like you, the english championship, but i got many bugs and i had to stop my game :/
now, i see yours and it seems thats working, so congrats and thanks for your efforts
now, maybe you can answer my questions about my bugged db.
first, i made a world league, but a bit different than yours. indeed, i swapped almost all teams from the 5 big championships (italy, spain, england, france, germany) and from brasil. i put all countries as EU-members, and lowered down the reputation of all the major leagues expected the english ones.
playing the game, i got that "2 matches the same day" bug, but otherwise, it worked fine, no major bugs. BUT, after i completed the first season (i finished 2th in the conference south div. and got the right to go in the superior division), i stayed in the conference south div. and especially there has been never again a new calendar so it was impossible to play anything !
i made my leagues the same than you, it means : unticked country in the div. fields before the swap and re-ticked them after, so it keeps the original countries rules etc...
so, i wonder why my game became impossible to play. Maybe have you some answers
ps: now, i'm gonna check your db and try to see differences. thanks again for your efforts.