Having played SO4, 5 & 6 I bought 7 but despite my previous successes SO7 is troubling me alot.

I have quality horses, all the facilities needed as well as top jockey and apprentice however, even on easy level performances are shockingly poor.

I even purchased a 3 time group 1 winning 3 year old but still results are awful.

I've followed advice from jockeys & head lad but to no available. I've even tried easy looking races with smaller fields.

What am I missing?

not sure you are missing much. the game isnt anywhere near as much fun as previous versions.

Without doubt SO7 is more challenging than the previous versions.

Some things that might be impacting your success is that the "stamina" attribute can be misleading and many of my horses run best further than it would indicate.
It also well known, even in SO6 that a purchased horses often do not live up to their pre-purchase performances.

I guess everyone's idea of fun is different, i love the increased difficulty. Makes winning a group one special, like it should be.
In SO6 i was able to break the game within 3 seasons and win GRP 1 races by 5 lengths.
I breed for the league so without stats and transfers its taken me 15+ seasons to breed up consistent Grp 1 winners.

Perhaps if you were able to post up a pic of one of your "quality" horses stats it might help identify any issues?

Cheers