I've learned to always read the setup instructions for any new groupset I encounter. Things have changed quite a bit since even 10 years ago when mounting F & R derailleurs was mostly the same procedure with only a couple little idiosyncrasies as compared to now with something like the OP's mounting issue. All mfrs publish instructions that can be easily found on the net if not included with the component. Even mounting the shifter cable on the wrong side of the clamp bolt is still a pretty common mistake so check out the instructions first.