Did it work for you as well?
I have a few more insights which i think are helpful
If you also have a national team manager contract and if between last match of the season for the club you have matches with the national team, you need to consider the club's last match of the season - i hope it makes sense.
So, to make it work, after you play last match of the season for the club, don't Advance, just go to squad sheets, remove the created players from starting 11 and subs, keep them in the Reserves and save the sheets. Then go to squad hub and renegotiate the contracts of created players. After this, don't make any changes to squad sheets or anything just proceed normally till next season.
This seems to work for me perfectly - i have reached season 6.
However, i don't know if it works for multiple created players, i just have 1.
Remember to keep backup saves so you can go back and repeat in case something goes wrong
I have 1 save before the club's last match of the season, 1 save just after that and 1 save i use to proceed my career on until next season.
I hope EA fixes this issue soon.
Till then, happy gaming! Cheers!