Hey, thought I'd give an update on this. Did another brew yesterday and after changing a few settings in brewfather I was still didn't hit the expected pre-boil and OG.
Pre-boil should have been 1.054 but was 1.044
OG should have been 1.065 but even after adding a my Belgian Candi syrup and some extra sucrose it still only came to 1.060.
My volumes were spot on though. Pre-boil 26.5l was fine and post-boil of 25l was fine.
So I can only assume my efficiency is wrong?
I did some more playing around in brewfather and found if I set my brewhouse efficiency to 63% it matches the numbers perfectly.
Could there be something wrong my process? That seems low